This topic provides answers to commonly asked questions about ECS instances.

How do I check which instance resources are available for purchase within a specific region or zone?

You can go to the ECS Instance Types Available for Each Region page to view the instance types available in each region.

What do I do if resources are sold out when I attempt to purchase an instance within a specific region or zone?

If the resources of a specific instance type are sold out when you attempt to purchase an instance of that instance type within a specific region or zone, take one of the following measures:
  • Select another region.
  • Select another zone.
  • Select another instance type.

If the resources that you want to purchase are still not available after you take all of the preceding measures, try again later. Instance resources are dynamic. When resources are insufficient, Alibaba Cloud replenishes them as soon as possible.

You can also use the arrival notice feature to receive notifications when resources become available.

How do I select an instance type that is suitable for my business?

Consider the following factors when you select an instance type. For more information about how to select an instance type, see Best practices for instance type selection.

  • Your business needs
  • Your website type
  • The average number of page views per day on your website
  • The size of your homepage
  • The data capacity of your website

How long does it take to create an ECS instance?

It takes a minute or two to create an ECS instance. After the instance is created:
  • For an ECS instance that runs a Linux operating system, you can connect to the instance without making any other configurations. For more information, see Connect to an ECS instance.
  • For an ECS instance that runs a Windows operating system, you must use the Sysprep tool to initialize the operating system. Do not restart the instance while the operating system is being initialized. After the operating system is initialized, you can connect to the instance. For more information, see Connect to an ECS instance. The amount of time required to initialize the operating system is determined by the type of the instance.
    • For an I/O optimized instance that runs a Windows operating system, two to three minutes are required to initialize the operating system.
    • For a non-I/O optimized instance that runs a Windows operating system, ten minutes are required to initialize the operating system.
Note If an error occurs while the instance is being created, submit a ticket.

I paid for an ECS instance but no ECS instance was created. Why?

If resources within the specified zone are insufficient to create an instance of your selected instance type, the instance fails to be created. Your account is automatically refunded the cost of the instance. If you do not receive a refund within half an hour, submit a ticket.

You can go to the ECS Instance Types Available for Each Region page to view the instance types available in each region.

Why are some instance types not available on the instance buy page when I attempt to purchase a pay-as-you-go instance?

Some of the instance types that have 16 or more vCPUs are available only to authorized accounts when the pay-as-you-go billing method is selected. If an instance type is available on the instance buy page when the subscription billing method is selected but is not available when the pay-as-you-go billing method is selected, submit a ticket to check whether your account is authorized to purchase pay-as-you-go instances of that instance type.

If your account is authorized but the instance type is still not available, the current region may not have sufficient resources for you to create pay-as-you-go instances of that instance type. For more information, see What do I do if resources are sold out when I attempt to purchase an instance within a specific region or zone?.

What are enterprise-level instances? What are shared instances?

Enterprise-level instances belong to a series of instance families released by Alibaba Cloud in September 2016. Enterprise-level instances provide high performance, consistent computing power, and balanced network performance. Enterprise-level instances have exclusive and consistent computing, storage, and network resources, and are suitable for enterprise scenarios that require high business stability.

Shared instances belong to a series of instance families that are targeted at individuals or small and medium-sized websites. Shared instances share resources, in contrast with enterprise-level instances that each have their own resources exclusively. As a result, shared instances do not provide consistent computing performance, but cost less.

What are the differences between enterprise-level and shared instances?

Enterprise-level instances use a CPU-bound scheduling scheme. Each vCPU is bound to a CPU hyperthread. Instances do not compete for CPU resources and do provide consistent computing performance as guaranteed in the SLA.

Shared instances use a CPU-unbound scheduling scheme. Each vCPU is randomly allocated to an idle CPU hyperthread. vCPUs of different instances compete for CPU resources, which causes computing performance to fluctuate when traffic loads are heavy. Shared instances can guarantee only availability but cannot guarantee the performance that may be required in the SLA.

Which instance families are enterprise-level instance families? Which instance families are shared instance families?

Among the instance families that are available for purchase, t6, t5, s6, n4, mn4, xn4, and e4 are shared instance families, and the rest are enterprise-level instance families.

In what business scenarios do I need to purchase enterprise-level instances?

For business scenarios to which different enterprise-level instances are applicable, see Instance families and Best practices for instance type selection.

How is the network performance of enterprise-level instances?

The network performance of enterprise-level instances depends on their specifications. The higher their specifications are, the higher network performance the instances can deliver. For more information about the network performance of different instance specifications, see Instance families.

Which disk categories do enterprise-level instances support?

For the disk categories that enterprise-level instances support, see Disk categories.

Which image types do enterprise-level instances support?

For the public images that enterprise-level instances support, see Overview.

You can also import custom images. For more information, see Import custom images.

What are the limits on changing the instance types of enterprise-level instances?

For the limits on changing the instance types of enterprise-level instances, see Instance families that support instance type changes.

Can I change a shared instance into an enterprise-level instance?

Yes, you can change a shared instance into an enterprise-level instance. For more information, see Instance families that support instance type changes.

What characteristics do persistent memory optimized instances have?

Persistent memory optimized instances use high-capacity persistent memory, and provide slower access and higher data durability than the instances that use regular memory do. When persistent memory optimized instances are stopped or restarted, data in their persistent memory is not lost. Persistent memory can be used as:
  • Memory: You can move some data from regular memory to persistent memory, such as non-hotspot data that does not require high-speed storage access. Persistent memory offers high capacity at a low price per GiB and can help reduce the total cost of ownership (TCO) of memory.
  • Local SSDs: Persistent memory can function like ultra-high performance SSDs to offer a read/write latency as low as 400 nanoseconds. Therefore, persistent memory is ideal for core application databases that require consistent response time. You can replace cache disks with persistent memory to achieve higher IOPS, higher bandwidth, and lower latency and improve the business performance of the entire cluster.

What requirements do persistent memory optimized instances have for operating systems?

The following image versions can be used on persistent memory optimized instances:

Alibaba Cloud provides support for Alibaba Cloud Linux 2. Alibaba Cloud Linux 2 integrates tools for scenarios to which persistent memory is applicable to work out of the box. In some scenarios such as scenarios where Redis applications are used, Alibaba Cloud Linux 2 outperforms community editions of Linux by 20%.

After I purchase a persistent memory optimized instance, how do I configure its persistent memory as memory?

You can use tools to configure the persistent memory as memory. For more information, see Configure the usage mode of persistent memory.

When persistent memory is used as memory on a persistent memory optimized instance, can I deploy and run Redis applications on the instance?

You can significantly reduce the memory TCO for Redis applications by running them on persistent memory optimized instances. However, to ensure performance, we recommend that you modify the Redis applications by classifying their data and storing the data in different places. You can store non-hotspot data in persistent memory and hotspot data in regular memory.

To reduce your modification costs, Alibaba Cloud provides re6p instance types specially for Redis applications. You can deploy Redis applications on instances of the re6p instance types by running several commands. For more information, see Deploy Redis applications on re6p instances.
Note When you purchase persistent memory optimized instances, select instance types named in the ecs.re6p-redis.<nx>large format.

I already have a Redis cluster based on regular memory and want to migrate business from this cluster to persistent memory optimized instances. How do I do this? What items do I need to take note of?

You must ensure business consistency and data reliability while you are migrating business from the Redis cluster to persistent memory optimized instances. We recommend that you first purchase a single persistent memory optimized instance and test it with a small amount of required business to check whether the basic performance and capacity model of the instance meet your business requirements. If the basic performance and capacity model of the instance meet your business requirements, you can scale out to more persistent memory optimized instances and take over from the entire Redis cluster.

Can I deploy and run a parameter server (PS) architecture on persistent memory optimized instances whose persistent memory is used as memory?

Server nodes in a PS architecture store all training parameters of training clusters, traditionally in their memory. These parameters consume a large amount of memory and are expensive to store. When you run a PS architecture on persistent memory optimized instances whose persistent memory is used as memory, we recommend that you store all parameters in persistent memory and only hash tables in regular memory. This way, the TCO of training clusters can be significantly reduced.

You can modify the applications to suit your business requirements,or submit a ticket to contact Alibaba Cloud for technical support.

After I purchase a persistent memory optimized instance, how do I configure its persistent memory as local SSDs?

You can use tools to configure the persistent memory as local SSDs. For more information, see Configure the usage mode of persistent memory.

To which applications are local SSDs that can deliver higher performance applicable?

To optimize performance or costs for I/O-intensive applications, you can select persistent memory optimized instances. You can use persistent memory optimized instances to solve common problems. Here are some of the problems:
  • The latency of single SQL queries is high or SQL queries require more consistent response time.
  • It takes too long to load resources on frontend servers of games, heavily loaded databases, and heavily loaded web servers.
  • You purchased large cloud disks or local disks for their high IOPS and bandwidth but now have unused capacity and unnecessary costs.

You can use persistent memory optimized instances in typical I/O-intensive scenarios such as:

Can I deploy Redis or MySQL applications on persistent memory optimized instances whose persistent memory is used as local SSDs? Do I need to modify the applications in the same way as I do when persistent memory is used as memory?

Yes, you can deploy Redis and MySQL applications on persistent memory optimized instances whose persistent memory is used as local SSDs. You do not need to modify these applications before they can identify the persistent memory as regular SSDs.

How is the performance of persistent memory used as local SSDs, compared with local NVMe SSDs and cloud disks?

You can perform the following steps to test the performance of the persistent memory when it is used as local SSDs:
  1. Configure persistent memory as local SSDs and attach the local SSDs to instances.

    For more information, see Configure the usage mode of persistent memory.

  2. Use disk performance test tools to test the performance of the local SSDs.

    For information about how to test disk performance by using fio in Linux systems, see the commands used in Test the performance of Elastic Block Storage devices.

How reliable is persistent memory?

The reliability of data stored in persistent memory depends on the reliability of persistent memory devices and the physical servers to which these devices are attached. This increases risks of single points of failure. To ensure the reliability of application data, we recommend that you implement data redundancy at the application layer and use cloud disks for long-term data storage.

When persistent memory optimized instances are released, data stored in their persistent memory is automatically cleared. We recommend that you back up data before you release the instances. It takes longer to release persistent memory optimized instances than to release other types of instances.

After the NVIDIA driver was installed, nvidia-smi did not work and an error message was returned indicating that the NVIDIA driver had not been installed. Why?

Cause: The mismatch between the kernel and kernel-devel package versions resulted in a driver compilation error when the driver was installed from the .rpm file.

Solution: Check the kernel version and download the corresponding kernel-devel package version. Then, run the rpm –qa | grep kernel command on the instance to check whether the kernel-devel package version matches the kernel version. Make sure that they match and then install the driver again.

Why doesn't Windows Graphics support DirectX-based functions?

Problem description: On Windows instances where the installed GPU driver has taken effect, Windows Remote Desktop Protocol (RDP) may not support DirectX- or OpenGL-based applications.

Solution: Install the VNC service and client or use other protocols that support these applications, such as PC over IP (PCoIP) and XenDesktop HDX 3D.

Do GPU-accelerated instances support Android emulators?

No, GPU-accelerated instances do not support Android emulators.

Can I change the configurations of GPU-accelerated instances?

You cannot change the configurations of the following GPU-accelerated instances:
  • GPU-accelerated instances with local storage
  • GPU-accelerated instances with virtual GPUs

For information about the GPU-accelerated instance families that support instance type changes, see Instance families that support instance type changes.

Do pay-as-you-go GPU-accelerated instances support the No Fees for Stopped Instances (VPC-Connected) feature?

Instance families such as gn5 that are equipped with local storage do not support the No Fees for Stopped Instances (VPC-Connected) feature. For more information, see No Fees for Stopped Instances (VPC-Connected).

How do I view GPU monitoring data?

You can log on to the Cloud Monitor console or call the DescribeMetricList operation to view GPU monitoring data. For more information, see GPU monitoring.

What are the differences between ECS bare metal instances, traditional cloud hosts (virtual machines), and traditional physical machines?

For information about the differences, see ECS Bare Metal Instance.

How is the network performance of ECS bare metal instances?

The network performance of ECS bare metal instances depends on their specifications. The higher their specifications are, the higher network performance the instances can deliver. For more information about the network performance of different ECS bare metal instance specifications, see Instance families.

Which disk categories do ECS bare metal instances support? How many data disks can be attached to a single ECS bare metal instance?

ECS bare metal instances support ultra disks and standard SSDs. Up to 16 data disks can be attached to a single ECS bare metal instance.

Can ECS bare metal instances have their configurations upgraded or downgraded? Do they support failover?

ECS bare metal instances cannot have their configurations upgraded or downgraded. They do support failover. When the physical machine that hosts an ECS bare metal instance fails, the system fails the instance over to another physical machine. Data is retained in the data disks of the instance.

How do I create an SCC instance?

You can create an SCC instance in one of the following ways:
  • If you only want to use the remote direct memory access (RDMA) feature, log on to the ECS console. Create an SCC instance as described in Create an SCC instance.
  • If you want to use the HPC scheduler and the cluster resizing service in addition to RDMA, log on to the E-HPC console. Create an SCC and then create an SCC instance.

How are SCC instances billed?

SCC instances can be billed on a weekly, monthly, or yearly subscription basis.

How do I create an SCC by using E-HPC?

You can log on to the E-HPC console or call the CreateCluster operation to create an SCC.

How do I use SCC RDMA?

If you select an image that is customized for SCC and supports RDMA RoCE drivers and OFED stacks to create an SCC instance, you can use SCC RDMA by virtue of the IB verbs API or implement RDMA communication by using the MPI.

I do not have overdue payments in my account. Why have my preemptible instances been released?

After the one-hour protection period of a preemptible instance expires, if the spot price (the current price per hour of the preemptible instance) exceeds the user-defined maximum hourly price or if resources are insufficient, the preemptible instance is automatically released.

Will I be notified when my preemptible instances are about to be released? How will I be notified?

Yes, you will be notified when your preemptible instances are about to be released. When your preemptible instance needs to be released due to a spot price change or insufficient resources, the instance first enters the To Be Released state and then is automatically released in five minutes.

You can use Cloud Monitor to subscribe to notifications for interrupted preemptible instances. For more information, see Set event notifications.

To check whether an instance is in the To Be Released state, you can view the instance metadata, or call the DescribeInstances operation and view the returned OperationLocks data.

Can the data of a preemptible instance be automatically retained when the instance is released?

No, the data of a preemptible instance cannot be automatically retained when the instance is released. When a preemptible instance is no longer needed, we recommend that you back up your data and environment by following the instructions in Create a snapshot and then release the instance. You can purchase new preemptible instances at any time.

Can I cancel or reschedule the automatic release of a preemptible instance?

Yes, you can cancel or reschedule the automatic release of your preemptible instance at any time.

Can preemptible instances be converted into subscription instances?

No, preemptible instances cannot be converted into subscription instances.

To what resources are the prices of preemptible instances applicable?

The prices of preemptible instances are applicable only to instance types. Other resources such as system disks, data disks, and network bandwidth are billed at the same prices as those of pay-as-you-go instances.

How do I bid for a preemptible instance?

To create a preemptible instance, you can specify a maximum hourly price to bid for an instance type. If the spot price does not exceed your specified maximum hourly price, the preemptible instance that you request is created and billed based on the spot price. For more information, see Create a preemptible instance.

What is the relationship between the user-defined maximum hourly price and the spot price of a preemptible instance?

If the spot price does not exceed the user-defined maximum hourly price, the preemptible instance is created and billed based on the spot price. After a preemptible instance is created, it enters a protection period in which it cannot be automatically released due to insufficient resources or fluctuations in the spot price.

After the protection period expires, the system checks the spot price and resource availability of the instance type every five minutes. If the spot price exceeds the user-defined maximum hourly price or if resources of the instance type are insufficient, the preemptible instance that is in the Running state is released.

Am I charged the same price for all preemptible instances started at the same time?

Yes, you are charged the same price for all preemptible instances started at the same time.

For the first hour after a preemptible instance is created, am I charged at a price that fluctuates with the spot price?

No, the hourly price of the first instance hour for a preemptible instance is set at the start of the hour and remains in effect for the whole hour.

Can I view the spot price of an instance type when I purchase a preemptible instance?

Yes, when you create a preemptible instance in the ECS console, you can view the spot price and historical prices of each selected instance type. The total instance price (including the instance type, storage, and bandwidth fees) is displayed in the lower part of the instance buy page. The instance type fee is the spot price of the selected instance type.

Can I view the historical prices of a preemptible instance type? How?

Yes, you can select an instance type to view its historical prices when you attempt to create a preemptible instance in the ECS console. You can also call the DescribeSpotPriceHistory operation to view the historical prices of a preemptible instance type.

Do preemptible instances continue to be billed after they are stopped?

Yes, preemptible instances continue to be billed after they are stopped. When a preemptible instance is no longer needed, we recommend that you back up your data and environment by following the instructions in Create a snapshot and then release the instance. You can purchase new preemptible instances at any time.
Note Preemptible instances continue to be billed after you stop them by using the ECS console or by calling the StopInstance operation.

How many preemptible instances can be purchased by a single account?

vCPU-based quotas, instead of instance count-based quotas, apply to preemptible instances in each account. When you create a preemptible instance, you can view the available vCPU-based quota after you select an instance type. For more information, see the "Instance limits" section in Limits.

How do I increase my vCPU-based quotas?

To increase your vCPU-based quotas, submit a ticket.

Can the instance type of a preemptible instance be changed?

No, the instance types of preemptible instances cannot be changed.

Which instance families support preemptible instances?

Instance families that support the pay-as-you-go billing method also support preemptible instances. If a preemptible instance of a specific instance type cannot be created due to insufficient resources, try a different instance type.

In which regions can I create preemptible instances?

Preemptible instances can be created within all Alibaba Cloud regions. If preemptible instances cannot be created within a specific region due to insufficient resources, try a different region.

When I attempt to purchase an ECS instance, the Preemptible Instance option is not available on the instance buy page. Why?

Whether the Preemptible Instance option is available depends on your ECS usage.

Which is more cost-effective: a preemptible instance with a protection period or a preemptible instance without a protection period?

Preemptible instances without a protection period are more cost-effective and have a discount of 10% off compared to preemptible instances with a protection period.

Is the release rate of preemptible instances without a protection period higher than that of preemptible instances with a protection period?

You can check the release rate of each instance type on the instance buy page in the ECS console regardless of whether you attempt to create preemptible instances with or without a protection period. For each instance type, the release rate is determined by the bidding policy and the supply-demand relationships of resources.release-rate

Are preemptible instances without a protection period prioritized for release over those with a protection period?

No, preemptible instances without a protection period are not prioritized for release over those with a protection period.

If I have created a preemptible instance without a protection period, do subsequently created preemptible instances also not have a protection period?

No, preemptible instances are created without a protection period only if you choose not to configure a protection period for them. By default, each preemptible instance is created with a protection period of one hour.
Note The protection period of preemptible instances can be configured only when the instances are created by calling API operations. For more information, see the description of the SpotDuration parameter in RunInstances and CreateInstance.

Will I be notified five minutes before a preemptible instance is released even if it does not have a protection period?

Yes, you will be notified five minutes before a preemptible instance is released even if it does not have a protection period.

Are fewer resources provided for preemptible instances with a protection period than for those without a protection period?

No, the same amount of resources are provided for preemptible instances with and without a protection period.

Can I convert between preemptible instances with and without a protection period?

No, you cannot convert between preemptible instances with and without a protection period. By default, each preemptible instance is created with a protection period of one hour. The protection period of preemptible instances can be configured only when the instances are created by calling API operations. The protection period settings of preemptible instances cannot be changed after the instances are created.

What are reserved instances?

Reserved instances automatically match pay-as-you-go instances (excluding preemptible instances) in your account to provide a billing discount. Reserved instances can also be used to reserve instance resources. A combination of reserved instances and pay-as-you-go instances provides higher cost-effectiveness and a higher degree of flexibility as compared with subscription instances.

Does a reserved instance provide a resource reservation?

Zonal reserved instances provide resource reservations, but regional reserved instances do not.

What operating systems do reserved instances support?

Reserved instances support both Windows and Linux operating systems. For example, a reserved Linux instance can be applied to any pay-as-you-go Linux instances that match its attributes regardless of the image type (public images, custom images, shared images, or Alibaba Cloud Marketplace images).

To apply a reserved instance to pay-as-you-go instances created from Bring Your Own License (BYOL) images, submit a ticket.

Which instance families do reserved instances support?

Reserved instances support the following instance families:
  • General purpose instance families: g6e, g6, g5, and sn2ne
  • Compute optimized instance families: c6e, c6, c5, ic5, and sn1ne
  • Memory optimized instance families: r6e, r6, r5, and se1ne
  • Big data instance family: d2s
  • Instance families with local SSDs: i2 and i2g
  • Instance families with high clock speed: hfc6, hfc5, hfg6, hfg5, and hfr6
  • GPU-accelerated compute optimized instance families: gn6i and gn6e
  • ECS Bare Metal Instance families: ebmc6, ebmg6, ebmr6, ebmhfc6, ebmhfg6, and ebmhfr6
  • Burstable instance families: t6 and t5

Can reserved instances be applied to preemptible instances?

No, reserved instances cannot be applied to preemptible instances.

Can the instance families of reserved instances be changed?

No, the instance families of reserved instances cannot be changed.

To what scenarios are zonal reserved instances applicable?

We recommend that you purchase zonal reserved instances when you have clear requirements to reserve resources.

To what scenarios are regional reserved instances applicable?

We recommend that you purchase regional reserved instances if you want to have a higher degree of zone flexibility or instance size flexibility.

How is the zone flexibility of reserved instances applied?

Only regional reserved instances provide zone flexibility. Example:

Assume that you are running the following pay-as-you-go instance:

One ecs.c5.xlarge Linux instance in Qingdao Zone B. This instance is named C5PAYG-b.

Assume that you have purchased the following reserved instance:

One regional ecs.c5.xlarge reserved instance in the China (Qingdao) region. This instance is named C5RI.

C5RI is matched to C5PAYG-b.

You release C5PAYG-b and start another Linux instance of the same instance type named C5PAYG-c in Qingdao Zone C. C5RI is then matched to C5PAYG-c.

How is the instance size flexibility of reserved instances applied?

Only regional reserved instances provide instance size flexibility. Example:

Assume that you have one regional ecs.g5.4xlarge reserved instance. It can be applied to one ecs.g5.4xlarge pay-as-you-go instance, two ecs.g5.2xlarge pay-as-you-go instances, or four ecs.g5.xlarge pay-as-you-go instances.

Assume that you have a one-year regional ecs.g5.xlarge reserved instance. It can be applied to offset the bills of an ecs.g5.xlarge pay-as-you-go instance or 50% of the bills of an ecs.g5.2xlarge pay-as-you-go instance by hour for one year.

Do zonal reserved instances provide instance size flexibility?

No, zonal reserved instances do not provide instance size flexibility. A zonal reserved instance can be applied only to pay-as-you-go instances of the same instance type as it.

Do zonal reserved instances provide zone flexibility?

No, zonal reserved instances do not provide zone flexibility. A zonal reserved instance can be applied only to pay-as-you-go instances in the same zone as it.

Can a zonal reserved instance be changed into a regional one?

Yes, a zonal reserved instance can be changed into a regional one. You can change the scope of a reserved instance you purchased in the following ways:

  • From a zone to a region
  • From a region to a zone
  • From one zone to another within the same region for a zonal reserved instance

Can the scope of a reserved instance be changed from one region to another?

No, the scope of a reserved instance cannot be changed from one region to another. For example, if you have a zonal reserved instance in Hangzhou Zone B, you can change the instance scope to another zone within the China (Hangzhou) region or change the instance into a regional reserved instance scoped to the China (Hangzhou) region. However, you cannot change the scope of the zonal reserved instance to a zone of another region, or change the instance into a regional reserved instance scoped to another region.

Can reserved instances be used across accounts?

No, reserved instances cannot be used across accounts.

Can reserved instances be used to cover the storage and network usage charges of pay-as-you-go instances?

No, reserved instances cannot be used to cover the storage or network usage charges of pay-as-you-go instances. Reserved instances cover the vCPU and memory costs of pay-as-you-go instances. For pay-as-you-go Windows instances, reserved instances also cover the image costs.

Can I configure a reserved instance to be applied to a specified pay-as-you-go instance?

No, you cannot configure a reserved instance to be applied to a specified pay-as-you-go instance. When multiple pay-as-you-go instances match the attributes of a reserved instance, the reserved instance is applied based on the optimized matching scheme.

How are reserved instances billed?

Reserved instances are billed separately and support the All Upfront, Partial Upfront, and No Upfront payment options.

The term of a reserved instance starts immediately after the instance is purchased. You are charged based on the payment option that you selected regardless of whether the reserved instance is matched to pay-as-you-go instances. The All Upfront option is most cost-effective.

When does a reserved instance take effect after it is purchased?

A reserved instance takes effect and is billed starting on the hour of your purchase. The reserved instance expires at 00:00:00 on the day after its term end date. For example, if you purchase a reserved instance with a term of one year at 13:45:00 on February 26, 2019, the reserved instance takes effect and is billed starting from 13:00:00 on February 26, 2019. The reserved instance expires at 00:00:00 on February 27, 2020. If you already have eligible pay-as-you-go instances when you purchase a reserved instance, the reserved instance is applied to offset the bills generated by the pay-as-you-go instances starting from the hour of 13:00 to 14:00 on February 26, 2019 until the reserved instance expires.

After I modify, split, or merge a reserved instance, when does the operation take effect?

When reserved instances are modified, split, or merged, new reserved instances are generated and the original ones become invalid. The new reserved instances take effect and the original ones become invalid. Both occur on the hours of the modification, splitting, or merging operations. Assume that you split one ecs.g5.2xlarge zonal reserved instance RI1 into two zonal ecs.g5.xlarge reserved instances RI2 and RI3 at 13:45:00 on February 26, 2019. At 13:00:00 on February 26, 2019, RI1 becomes invalid and RI2 and RI3 take effect. Starting from 13:00:00 on February 26, 2019, the instance type eligible for resource reservation and billing discounts is ecs.g5.xlarge, not ecs.g5.2xlarge any more. If RI2 and RI3 are matched to pay-as-you-go instances immediately after they take effect, RI2 and RI3 are also applied to offset the hourly bills of ecs.g5.xlarge pay-as-you-go instances starting from 13:00:00 on February 26, 2019.

Why isn't the No Upfront payment option displayed on the buy page?

The availability of this option depends on your ECS usage.

Can the payment option of a reserved instance be changed?

No, the payment options of reserved instances cannot be changed.

Can reserved instances be resold?

No, reserved instances cannot be resold.

Can I use reserved instances to cover the image costs of pay-as-you-go Windows instances?

Yes, reserved instances can be used to cover the image costs of pay-as-you-go Windows instances. This is because reserved Windows instances already include Windows images at no additional cost.

Can reserved instances be used to cover the image costs of pay-as-you-go Linux instances?

No, reserved instances cannot be used to cover the image costs of pay-as-you-go Linux instances.

Are the consumption details of reserved instances refreshed each hour?

Yes, the consumption details of reserved instances are refreshed each hour.

Can a reserved instance be applied to more than one pay-as-you-go instance at the same time?

Yes, a reserved instance can be applied to more than one pay-as-you-go instance at the same time. The reserved instance checks for eligible pay-as-you-go bills on an hourly basis and deducts fees based on its computing power.
Note The computing power and term of each reserved instance are fixed. You cannot increase the computing power of a reserved instance by shortening its term.
Assume that you have a reserved instance with the following attributes:
  • c5.large instance type
  • Instances: 1 (indicating that the reserved instance can match one pay-as-you-go instance of the specified instance type)
  • One-year term
The following examples demonstrate how the reserved instance is applied based on the pay-as-you-go instances that exist:
  • Six c5.large pay-as-you-go instances exist for one hour each. Each of these pay-as-you-go instances consumes one hour of computing power equal to that delivered by the c5.large reserved instance every hour. The reserved instance is applied randomly to one of the pay-as-you-go instances. You cannot configure the reserved instance to be applied to all six pay-as-you-go instances by shortening the term of the reserved instance to two months.
  • Six c5.large pay-as-you-go instances exist for 10 minutes each. The six instances consume 10 minutes of computing power each and in total consume the amount of computing power that the c5.large reserved instance can deliver every hour. The reserved instance is applied to all six pay-as-you-go instances.
  • Six c5.large pay-as-you-go instances exist for 15 minutes each. The six instances consume 15 minutes of computing power each, in total exceeding the amount of computing power that the c5.large reserved instance can deliver every hour. The reserved instance is applied randomly to the pay-as-you-go instances to offset the charges for one hour of computing power.

Does a VNC management terminal allow multiple users to log on simultaneously?

No, a VNC management terminal allows a single user to log on at a time.

What do I do if I forget the remote connection password?

You can reset your remote connection password. For more information, see Modify the VNC password.

Why am I unable to connect to a VNC management terminal even after I reset my remote connection password?

If the instance to which you are connecting is not I/O optimized, you must restart the instance by using the ECS console or by calling the RebootInstance operation for the new password to take effect.
Note If you restart the instance from within the instance, the new password does not take effect.

I was prompted with an authentication failure when I attempted to connect to a VNC management terminal. What do I do?

Authentication fails if the entered password is not correct. Perform the following troubleshooting operations:
  1. Enter the correct remote connection password.
  2. If you forget your password, you can reset it and try again. For more information, see Modify the VNC password.
    Note If the instance to which you are connecting is not I/O optimized, you must restart the instance by using the ECS console or by calling the RebootInstance operation for the new password to take effect.

What do I do if a black screen appears while I am connected to a VNC management terminal?

A black screen indicates that the instance is in sleep mode. Perform the following operations based on your operating system:
  • For a Linux instance, click your mouse or press any key to activate the instance.
  • For a Windows instance, you can choose Send Remote Call > CTRL+ALT+DELETE in the upper-left corner to go to the logon interface.

What do I do if a VNC management terminal cannot be accessed?

You can use a browser to access the VNC management terminal for troubleshooting. For example, use Google Chrome to access the VNC management terminal, and press the F12 key to open the developer tools panel. Then, click the Console tab and identify errors based on the information displayed.

Why am I unable to use Internet Explorer 8 to access a VNC management terminal?

VNC management terminals support Internet Explorer 10 and later.

We recommend that you use Google Chrome because it is most compatible with the Alibaba Cloud Management Console.

When I use Firefox to access a VNC management terminal, an error message is returned indicating that the secure connection has failed. What do I do?

This problem occurs if the encryption algorithm used by your version of Firefox is different from that used by the VNC management terminal.

We recommend that you use Google Chrome because it is most compatible with the Alibaba Cloud Management Console.

How do I remotely log on to a Linux instance?

Linux instances support SSH for remote connection. You can use one of the following methods to remotely log on to a Linux instance:

What are the default username and password for remote logon to the operating system of an ECS instance?

The default username varies by operating system.
  • For a Windows instance, the default username is administrator.
  • For a Linux instance, the default username is root.
The password for remote logon to the operating system of an instance is set by yourself when you create the instance. For more information, see Create an instance by using the wizard. If you forget the password, you can reset it. For more information, see Reset the logon password of an instance.
Note This password is used to remotely log on to the instance operating system, not to the VNC management terminal.

How do I adjust the desktop resolution of a Windows instance?

You can use one of the following methods to adjust the desktop resolution of a Windows instance:
  • Connect to the instance by using a VNC management terminal and adjust the desktop resolution on the instance.

    The following example demonstrates how to adjust the desktop resolution of an instance that runs a Windows Server 2019 Datacenter 64-bit operating system:

    1. Connect to the ECS instance by using a VNC management terminal in the ECS console. For more information, see Connect to a Windows instance by using VNC.
    2. On the Windows desktop, right-click a blank area and select Display settings.
    3. In the Scale and layout section, adjust the resolution.
  • Use the Remote Desktop Connection (RDC) tool on your local computer.
    You cannot adjust the desktop resolution of a Windows instance after you connect to the instance from your local computer by using RDC. You must adjust the display settings in RDC on the local computer, and then connect to the instance by using RDC to apply the new display settings to the instance.windows

What do I do if I fail to deploy a Data Plane Development Kit (DPDK) application on an ECS instance?

We recommend that you deploy DPDK applications on g5ne instances. For more information about the g5ne instance types, see Instance families.

If you deploy DPDK applications on ECS instances of the sixth-generation and later instance types (such as g6, c6, and r6 instance types), the bound igb_uio port may not be detected when you use Pktgen-DPDK to perform tests, and the following error is reported:
EAL: eal_parse_sysfs_value(): cannot open sysfs value /sys/bus/pci/devices/0000:00:09.0/uio/uio0/portio/port0/start
If you use DPDK 19.05, you can troubleshoot the problem by installing patches. You can submit a ticket to obtain the patches and run the following commands to install them:
cd dpdk
copy virtio0.95_bar0_memebar.diff to dpdk
git apply virtio0.95_bar0_memebar.diff

Can I upgrade the instance types and other configurations of subscription instances?

Yes, you can upgrade the instance types and other configurations of subscription instances. For more information, see Upgrade the instance types of subscription instances.

Can I upgrade the instance types and other configurations of pay-as-you-go instances?

Yes, but you must stop pay-as-you-go instances before you can upgrade their instance types and other configurations. You can upgrade the instance types and other configurations of pay-as-you-go instances by following the instructions in Change the instance type of a pay-as-you-go instance or by calling the ModifyInstanceSpec operation.

How long does it take to upgrade the configurations of an instance?

  • Subscription instances do not need to be stopped for their instance types to be upgraded. It takes about 15 minutes to upgrade the instance type of a subscription instance.
  • Pay-as-you-go instances must be stopped for their instance types to be upgraded. It also takes about 15 minutes to upgrade the instance type of a pay-as-you-go instance.
  • You can upgrade the bandwidths of instances without stopping the instances. The upgrade process takes about five minutes.

How is the fee for an instance configuration upgrade calculated?

The fee and its calculation method are displayed in the ECS console when you upgrade the instance type or other configurations of an instance. You can also view the billing details on the Account Overview page.

Are my cloud service configurations affected if I upgrade the configurations of ECS instances?

Pay-as-you-go instances must be stopped before their configurations can be upgraded. After you upgrade the configurations of a subscription instance, you must restart the instance for the new configurations to take effect. The upgrade operation interrupts the services that run on the instance for a short period of time. We recommend that you upgrade the configurations of instances during off-peak hours. Instances can seamlessly resume services after upgrades without environment reconfiguration.

How do I upgrade ECS resources?

For information about how to upgrade ECS resources, see Overview of instance upgrade and downgrade.
  • With the exception of ECS instances that use local storage, ECS instances allow their CPU and memory resources to be scaled and their bandwidths to be upgraded while the instances are running. You can also downgrade the configurations of ECS instances.
  • A maximum of 16 data disks can be attached to each ECS instance. You cannot reduce the size of a data disk after it is extended.
  • The bandwidth of each ECS instance is measured in Mbit/s and can range from 0 Mbit/s to 200 Mbit/s. You can also temporarily upgrade the bandwidth of an ECS instance, or downgrade the configurations of the instance when you renew it.

I have upgraded the configurations of an instance but no changes have taken effect. Why?

After you upgrade the configurations of an instance, you must restart the instance by using the ECS console or by calling an API operation for the new configurations to take effect.

What do I do if I cannot access a website that runs on an ECS instance?

For information about how to solve this problem, see Unable to access the website running on ECS instances.

If the problem persists, submit a ticket.

My ECS instance was stuck in the Starting state, and AliyunService was disabled or deleted. What do I do?

Problem description: After an ECS instance was started, it stayed in the Starting state for an extended period of time and then automatically stopped. You logged on to the instance and found that AliyunService was deleted or disabled in the system services.

Solution:
  • If AliyunService was disabled:
    1. Change the state of AliyunService to automatic.
    2. Restart the instance.
  • If AliyunService was deleted:
    1. Run the following command to add AliyunService to the instance:
      sc create AliyunService type= "own" start= "auto" binPath= "C:\Program Files\AliyunService\AliyunService.exe -d" tag= "no" DisplayName= "AliyunService"
      Note Make sure that you leave a space after each equal sign (=).
    2. Find the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\AliyunService, and change c:\Program Files\AliyunService\AliyunService.exe -d to "c:\Program Files\AliyunService\AliyunService.exe" -d.
    3. Restart the instance.

How do I use f1 instances?

After you create an f1 instance, Alibaba Cloud shares an FPGA development image to you. Currently, only CentOS 7u2 images are supported. The FPGA development image includes the complete Intel Quartus development suite and the f1 instance constraint files to provide a complete cloud development environment.

Note You can go to the ECS Instance Types Available for Each Region page to view the instance types available in each region.
The following section describes the basic workflow to use an f1 instance:
  1. After development is complete, you can generate an intermediate QAR file during the compilation stage and upload the file to an OSS bucket. Currently, you can upload this file only to an OSS bucket within the China (Hangzhou) region. Then, you can register the QAR file information with Alibaba Cloud by calling an API operation.

    We recommend that you use the free Intel Quartus development suite to complete development, compilation, and simulation operations on the cloud.

  2. Alibaba Cloud verifies your registration request for the QAR file, and sends you an email that includes an FPGA image ID if the verification is successful.
  3. To deploy the image, you can call an API operation with the f1 instance ID and FPGA image ID specified to associate the instance with the image.

    You can initiate the association operation in all scenarios where ECS API is available.

    • If the f1 instance has never been associated with any FPGA image, initiate the association operation.
    • If the f1 instance was previously associated with an FPGA image and had the image loaded, erase the FPGA image from the f1 instance before you initiate the association operation.
  4. After you associate the FPGA image with the instance, call an API operation to load the image.

    You must initiate the load operation from the f1 instance. Then, the underlying service of Alibaba Cloud burns the associated FPGA image to the corresponding FPGA on the instance.

If you want to restore the f1 instance to its initial state, call an API operation to erase the burned FPGA image from the f1 instance.

For more instructions on how to manage f1 instances, see the following topics:

How do I upload files by using the FTP tool in macOS?

Method 1: Upload files by using the Terminal of macOS

Open the Terminal in macOS or iTerm2 for Mac (click here to download iTerm2). Make sure that you select the correct destination path.

  1. Connect to the FTP server.
  2. Access the destination directory. In Windows, use the working directory as the destination directory. In Linux, switch to the htdocs directory and use it as the destination directory.
  3. Run the put command to upload files.

Method 2: Upload files by using a third-party tool

  1. Download Yummy FTP.
  2. Install Yummy FTP.
  3. Enter the server IP address, username, and password. Set Protocol to Standard (FTP). Set Port to 21 or a different port number that you are using, and leave the SSH key field unselected.
  4. Click Connect.
  5. In the right-side pane, select the destination directory. In Windows, use the current working directory. In Linux, select the htdocs directory. In the left-side pane, select files and click the Upload icon to upload the files.
    Note If you attempt to install Yummy FTP and are prompted with a message similar to "Your security preferences only allow the installation of applications from the Mac App Store and authorized developers", perform the following steps:
    1. Choose System Preference > Security and Privacy.
    2. Click the security lock in the lower-left corner of the window and enter the administrator password.
    3. Set Allow apps download from to Anywhere.

    Then, you can upload files by using Yummy FTP.

If you have further questions, submit a ticket.

How do I apply for an ICP filing for my domain name after I purchase an ECS instance?

For each ECS instance, you can apply for a limited quantity of service identification numbers for ICP filings. For more information, see Prepare and check the instance and access information.

An ECS instance fails to load the kernel to start up. What do I do?

Problem description: The system does not respond when you select an option from the GRUB menu on system startup. After you have mounted the LiveCD image to the ECS instance, you can log on to the instance and confirm that the file system privileges are correct and that the message logs show no exceptions.

Cause: The system has been attacked by ransomware.

Solution: Back up your data and re-initialize the system.

For more information, see Recover from ransomware attacks.

How do I change the logon password from within an instance?

For information about how to change the logon password from within an instance, see Change the logon password of an instance by connecting to the instance.

Why am I unable to add sound or video cards to ECS instances?

The servers that Alibaba Cloud ECS provides are not multimedia servers and do not provide sound or video card components. Sound or video cards cannot be added to ECS instances.

Can I transfer the unused time of an ECS instance to another ECS instance?

No, the unused time of an ECS instance cannot be transferred to others. If you want both higher flexibility and cost-effectiveness, we recommend that you use a combination of reserved instances and pay-as-you-go instances. For more information, see Reserved instance overview.

Do ECS instances provide databases by default?

No, ECS instances do not provide databases by default. To use database services, perform the following operations:
  • Deploy your own database.
  • Purchase ApsaraDB RDS provided by Alibaba Cloud.
  • Use a database image provided in Alibaba Cloud Marketplace.

Can I build a database on an ECS instance?

Yes, you can install database software and configure a database environment on an ECS instance. You can also purchase ApsaraDB RDS separately.

Do ECS instances support Oracle databases?

Yes, ECS instances support Oracle databases. Before you install an Oracle database, we recommend that you perform a performance stress test on the ECS instance to ensure that the instance satisfies the read/write requirements of the database.

Are public and private IP addresses independent? Can I specify or add IP addresses?

In the classic network, public and private IP addresses are independent of each other. Private IP addresses in the classic network are used for communication between ECS instances and between ECS instances and OSS buckets or ApsaraDB RDS instances. If the public bandwidth of an ECS instance is set to 0 Mbit/s, no public IP address is assigned to the instance. In normal cases, public and private IP addresses in the classic network do not change. You cannot specify, select, or add IP addresses in the classic network.

In VPCs, NAT gateways map public IP addresses to private IP addresses. You can add IP addresses by specifying or automatically assigning secondary private IP addresses to ENIs.

Can load balancing be implemented for a single ECS instance?

Both Linux and Windows ECS instances can be load-balanced. Make sure that the configurations of ECS instances used as web servers meet the requirements for website code to run. Load balancing can be implemented for as few as one ECS instance in an account. However, we recommend you implement load balancing for two or more ECS instances.

Can I change the region of an ECS instance?

No, the regions of purchased ECS instances cannot be changed. To change the region of an ECS instance, you can use the ACS-ECS-CloneInstancesAcrossRegion public template provided by Operation Orchestration Service (OOS) to copy the instance to another region. The new and original instances have identical disk data but different IP addresses.

Can I adjust the partition size of a purchased disk?

For system security and stability purposes, system disks cannot be repartitioned on either Windows or Linux instances. If you use a third-party tool to repartition system disks, unknown exceptions such as system failures and data losses may occur.

If you repartition a data disk, data may be lost. We recommend that you do not repartition data disks.

How do I replace the automatically assigned public IP address of an ECS instance with an elastic IP address (EIP)?

To replace the automatically assigned public IP address of an ECS instance with an EIP, make sure that the instance uses the pay-by-bandwidth billing method for network usage and that you have purchased an EIP. Then, use one of the following methods to do the replacement:

How do I view subscription ECS instances within all regions in my account?

You can go to the Renewal page to view subscription ECS instances within all regions in your account.
  1. Log on to the ECS console.
  2. In the top navigation bar, choose Expenses > Renewal Management.

When can I forcibly stop an ECS instance? What are the consequences?

If an instance cannot be stopped by a proper shutdown procedure, you can forcibly stop the instance. A forced stop is equivalent to disconnecting the power from the instance, and can result in loss of unsaved data.

Why am I unable to reactivate my ECS instance?

An instance may fail to be reactivated due to one of the following reasons:
  • You have overdue payments in your account. Pay the outstanding bills and try again.
  • The system is busy. Try again later.
  • Resources of the specified instance type are sold out.
    Note You can go to the ECS Instance Types Available for Each Region page to view the instance types available in each region.

Why has an ECS instance with release protection enabled been automatically released from a scaling group?

Auto Scaling can automatically release an ECS instance created by a scale-out event even if you have enabled release protection for the instance by using the ECS console or by calling the ModifyInstanceAttribute operation.

To prevent the ECS instance from being automatically released, you must change its status to Protected in the Auto Scaling console. For more information, see Put an ECS instance into the Protected state.

What is the AliVulfix process in an ECS instance?

The AliVulfix process is an Alibaba Cloud Security program that scans ECS instances for vulnerabilities.

How do I protect ECS instances against attacks?

ECS instances use Alibaba Cloud Security to defend against DDoS attacks. Cloud Monitor deployed on ECS instances can automatically detect network attacks and scrub suspicious traffic. Alibaba Cloud implements black hole filtering to protect ECS instances against high-volume attacks. To strengthen security protection, we recommend that you install security software and disable ports that are not commonly used.

What security services does Alibaba Cloud provide?

Alibaba Cloud Security is powered by the robust data analysis capabilities of the Alibaba Cloud cloud computing platform to provide a comprehensive set of security services such as security vulnerability detection, website trojan detection, host intrusion detection, and anti-DDoS protection.

For information about more security services, see Alibaba Cloud Security Services.

I have already renewed an expired Linux instance but I am still unable to access the website hosted on it. What do I do?

Problem description: A Linux ECS instance is in the Stopped state after it has expired. After you have renewed and restarted the instance, you still cannot access the website hosted on it.

Cause: This may be because the website service has not been started.

Solution:
  1. Connect to the instance and run the following command to check whether the website service has been started:
    # netstat -nltp //Check whether port 80 on the instance is being listened on.
  2. If no information about port 80 is displayed in the command output, the website service has not been started. Run a command to manually start the website service and relevant services.

    In Linux, websites are typically developed based on PHP and MySQL.

    • In Apache, you only need to start the website service and MySQL.
      #/etc/init.d/httpd start          //Start the website service. This command is applicable to Apache.
      #/etc/init.d/mysqld start         //Start MySQL.
    • In NGINX, you must start the website service, PHP, and MySQL.
      #/etc/init.d/nginx start          //Start the website service. This command is applicable to NGINX.
      #/etc/init.d/php-fpm start        //Start PHP.
      #/etc/init.d/mysqld start         //Start MySQL.
  3. Check again whether the website service has been started.
    #netstat -nltp //Check whether port 80 on the instance is being listened on.
  4. After the website service has been started, access the website again.

If the problem persists, submit a ticket.

How do I activate a Windows ECS instance in a VPC?

To activate a Windows ECS instance in a VPC, you must use a specific KMS domain name. For more information, see How to activate the VPC-Connected Windows instances using KMS servers.

How do I query, partition, and format the disks of a Linux instance?

You can run the df –h command to check the capacity and usage of disks, and run the fdisk –l command to view disk information. For information about how to partition and format the disks of Linux instances, see Format a data disk for a Linux instance.

How do I upload files to a Linux instance?

You can use the FTP service to upload files to a Linux instance.

How do I change the owner and owner group of directories and files on a Linux instance?

If the file or directory permissions are not correctly configured on the web server, a 403 error is reported when you access a website hosted on the instance. Before you adjust a file or directory, you must identify the identity under which the file or directory process is running.

You can run the ps and grep commands to query the identities under which processes are running.

You can run the ls –l command to query the owners and owner groups of files and directories.

To change the owners and owner groups, run the chown command. For example, you can run the chown -R www.www /alidata/www/phpwind/ command to change the owner and owner group of all files and directories under the /alidata/www/phpwind directory to Account www.

How do I update the software repository for Linux instances?

You can use an automatic tool to update the software repository for Linux instances. For more information, see Automatic source updating tool for Linux ECS.

What limits apply to the transfer and change of public IP addresses of ECS instances?

The following limits apply to the transfer and change of public IP addresses of ECS instances:
  • In the classic network:
    • You cannot transfer public IP addresses across accounts.
    • The public IP address of an ECS instance can be changed within six hours after the instance is created, and can be changed a maximum of three times. For more information, see Change the public IP address of an ECS instance.
    • If Anti-DDoS Pro is deployed, you can change the IP address of an ECS instance a maximum of 10 times by using the Anti-DDoS Pro console. For more information, see the Change ECS IP section in Anti-DDoS Pro User Guide.
  • In VPCs:
    • You cannot transfer public IP addresses or EIPs across accounts.
    • If no public IP address is assigned to your instance, you can associate an EIP with the instance. You can replace the public IP address of your instance with an EIP.
    • If a public IP address is assigned to your instance while the instance is being created:

If you have further questions, submit a ticket.

Can I access amazon.com from my ECS instance?

You can access amazon.com from your ECS instance if the instance can connect to the Internet properly.

Why am I unable to access a website hosted outside mainland China after I log on to my ECS instance?

You can access a website hosted outside mainland China from your ECS instance only when the website complies with the laws, regulations, and regulatory requirements of the country or region where your instance is located. Make sure that your ECS instance can connect to the Internet properly and that the website complies with the preceding laws, regulations, and regulatory requirements.

I cannot purchase more pay-as-you-go instances. What do I do?

If you have reached the maximum number of pay-as-you-go instances that you can purchase, you cannot purchase more pay-as-you-go instances. For more information, see the "Instance limits" section in Limits. You can log on to the ECS console and click Privileges in the upper-right corner of the Overview page to view your resource quotas. For more information, see View quotas (old version).

How can I view the resource quota?

For more information about how to view the limits and quotas of resources, see Limits.

Am I still charged for a pay-as-you-go instance after it is stopped either manually or due to an overdue payment?

Stopped due to an overdue payment: When a payment becomes overdue in your account, your pay-as-you-go instance is automatically stopped and billing for this instance stops. Instances do not always stay in the Stopped state after they are stopped due to overdue payments. For more information, see Pay-as-you-go.

Manually stopped: You can stop a running pay-as-you-go instance by using the ECS console or by calling the StopInstance operation. When the instance is stopped, its status changes to Stopped. Billing for stopped pay-as-you-go instances is based on their network types.
  • VPC: You can enable the No Fees for Stopped Instances (VPC-Connected) feature.
    • After the feature is enabled, billing for pay-as-you-go instances in VPCs starts when the instances are created, stops when the instances enter the Stopped state, and resumes when the instances are started. When a pay-as-you-go instance enters the Stopped state, the No Fees for Stopped Instances (VPC-Connected) feature stops billing only for the vCPUs, memory, and public IP address of the instance. Other resources such as disks and EIPs of the instance continue to be billed. For more information, see No Fees for Stopped Instances (VPC-Connected).
    • After the feature is disabled, billing for pay-as-you-go instances continues when they are stopped.
  • Classic network: ECS instances in the classic network are billed regardless of whether they are in the Stopped state.

What do I do if an order cannot be placed to change the billing method of an instance from pay-as-you-go to subscription?

You may be unable to place the order due to one of the following reasons:
  • The instance is in a state that does not support changes to the billing method. For example, the instance has an unpaid order.
  • Changes to the billing method are not allowed due to an upcoming scheduled automatic release.
  • Changes to the billing method are not allowed because the instance information has changed.
  • A previous order to change the billing method of the instance has not been paid.

If one of the preceding errors is reported, adjust the instance accordingly.

How long after an order is paid does it take to change the billing method of an instance from pay-as-you-go to subscription?

The billing method of your ECS instance is changed after the order is paid. It can take up to four seconds to change the billing method of 20 instances. After the change is complete, you can see that the billing method of your instance has been changed to Subscription in the ECS console.

What do I do if the billing method of an instance cannot be changed from pay-as-you-go to subscription?

Submit a ticket.

When I change the billing method of an instance from pay-as-you-go to subscription, does the billing method for network usage of the instance also change?

No, the billing method for network usage of the instance does not change. Only the billing method of instances and disks can be changed from pay-as-you-go to subscription. For information about how to change the billing method for network usage, see Overview of instance upgrade and downgrade.

I have an unpaid order to change the billing method of an instance from pay-as-you-go to subscription. If I upgrade the configurations of the instance, is the order still valid?

An order is created when you change the billing method of your instance from pay-as-you-go to subscription. You must pay for the order to complete the change. If you upgrade the configurations of the instance before the order is paid, the order payment cannot be completed because the instance components are different and the original order no longer matches. If you still want to change the billing method of your instance, you must cancel the unpaid order and place a new order.

What do I do if the billing method of an instance cannot be changed from subscription to pay-as-you-go?

You may be unable to change the billing method of an instance from subscription to pay-as-you-go due to one of the following reasons:

  • The instance is in a state that does not support changes to the billing method. For example, the instance has an unpaid order.
  • The instance is in the Expired state.
  • The instance information has changed. For example, the bandwidth of the instance has been temporarily upgraded.

If one of the preceding errors is reported, adjust the instance accordingly. If the problem persists, submit a ticket.

When I attempt to change the billing method of a disk in an ECS instance, an error message is returned indicating that I have already changed the billing method three times. What does this mean?

Each ECS instance can have its configurations downgraded a maximum of three times. Downgrade operations include downgrades of instance specifications, bandwidth downgrades, and the change of the disk billing method from subscription to pay-as-you-go.

Why am I unable to change a pay-as-you-go instance into a subscription one?

The pay-as-you-go instance that you want to change must meet the following requirements:
  • The instance type of the instance is not retired. For more information, see Phased-out instance types.
  • The instance is not a preemptible instance.
  • No unpaid orders related to the instance exist.

    If unpaid orders related to the instance exist, you must pay for the orders or cancel the orders before you change the billing method of the instance.

  • Automatic release time is not configured for the instance.

    If automatic release time is set for the instance, you must disable the automatic release configuration before you change the billing method. For more information, see Disable automatic release.

  • The instance is in the Running or Stopped state.

    Example: An order to change the billing method was placed while the ECS instance is in the Running or Stopped state. However, the instance status changes before the payment was attempted. The order fails and the billing method does not change. You can go to the Billing Management console and pay for the order when the instance is in the Running or Stopped state again.

How do I view the expiration time of a subscription instance?

You can log on to the ECS console and go to the Instances page to view the expiration time of your subscription instance in the Billing Method column.

Note If the Billing Method column is not displayed, click the icon in the upper-right corner. In the Column Filters dialog box, select Billing Method and click OK.