Elastic Compute Service (ECS) may have limits on features, performance metrics, and related quotas. Some limits can be raised by increasing quotas. To ensure that available ECS resources meet your business requirements, we recommend that you learn about the limits, plan for resources, and apply for quota increases or mitigate the impacts of the limits that cannot be raised in advance. This topic describes the limits on ECS resources and how to increase specific quotas.
Table dimensions
You can view the table in each section of this topic to learn about the limits on the corresponding features, performance metrics, and quotas. The following section describes the dimensions in the tables:
Item: a feature, performance metric, or quota.
NoteA quota refers to the maximum number of resources or operations allowed for an Alibaba Cloud account.
Limit: the limits on an item.
If an item is an ECS quota, you can query the quota by quota ID to obtain the limit of the quota.
Method to raise limits: the methods available to raise the limits on an item.
If you cannot raise the limits on an item, you must mitigate the impacts of the limits in advance. If you can raise the limits, use a suitable method to apply for a quota increase as needed.
Instances
Item | Limit | Method to raise limits |
vCPU-based quotas | The maximum number of vCPUs on all ECS instances that belong to a specific instance family and use a specific billing method such as subscription, pay-as-you-go, or Preemptible Instance within an Alibaba Cloud account per region. For information about the limits, see the vCPU-based quotas section of this topic. | |
GPU- and vGPU-based quotas | The maximum number of GPUs or vGPU-accelerated instances among all ECS instances that belong to a specific instance family and use a specific billing method such as subscription, pay-as-you-go, or Preemptible Instance within an Alibaba Cloud account per region. For information about the limits, see the GPU- and vGPU-based quotas section of this topic. | |
The maximum number of subscription instances that an Alibaba Cloud account can purchase per time in a specific region | You can view the quota based on the quota ID | N/A |
Change the billing method of instances from pay-as-you-go to subscription |
| N/A |
Change the billing method of instances from subscription to pay-as-you-go | A refund generated from the billing method change is counted against the monthly refund quota. If the refund quota for the current month is exhausted, you cannot request new refunds within the month. In this case, you cannot change the billing method of instances from subscription to pay-as-you-go. For more information, see Change the billing method from subscription to pay-as-you-go. Note The refundable amount is displayed on the page on which you change the billing method of instances. The refunded amount is automatically set to 0 on the first day of the next month. | N/A |
Secondary virtualization | Only ECS Bare Metal Instance families and Super Computing Cluster (SCC) instance families support secondary virtualization. Other ECS instance families do not support virtualization software installation or secondary virtualization. | N/A |
Sound card applications | ECS does not support sound card applications. | N/A |
External hardware devices | You cannot directly attach external hardware devices, such as hardware dongles, USB flash drives, external hard disks, and bank U keys, to ECS instances. However, you can use software verification methods, such as software dongles and two-factor authentication based on one-time passwords. | N/A |
Multicast protocols | ECS does not support multicast protocols. Use unicast protocols instead. | N/A |
Internet Content Provider (ICP) filing for websites and applications | If you want to apply for an ICP filing for a website or an application, you must purchase an ECS instance with a subscription duration of at least three months. You can apply for ICP filings for up to five websites or applications for each ECS instance. For more information, see Check the instance for ICP filing. | N/A |
Licenses | Specific software or application licenses must be bound to the hardware of ECS instances. After you migrate an ECS instance, its hardware information may change. As a result, the licenses bound to the original hardware become invalid. | N/A |
vCPU-based quotas
GPU- and vGPU-based quotas
Images
Item | Limit | Method to raise limits |
The maximum number of custom images that an Alibaba Cloud account can retain per region | You can view the quota based on the quota ID | |
The maximum number of accounts with which you can share a custom image | You can view the quota based on the quota ID | |
Images supported by instance types | Instance types with 4 GiB of memory or more do not support 32-bit images. | N/A |
For more information about images, see Overview.
Block storage devices
Item | Limit | Method to raise limits |
System disks per instance | 1 | N/A |
The maximum number of data disks per instance | The maximum number of data disks that you can attach to an ECS instance varies based on the instance type. For more information, see Overview of instance families. Note You can attach only one system disk and up to 16 data disks to an instance when you create the instance. If the instance requires additional data disks, attach more data disks after the instance is created. You can call the DescribeInstanceTypes operation to query the maximum number of disks allowed for an instance of a specific instance type. | N/A |
The cloud disk capacity quota for an Alibaba Cloud account in a specific region and zone | The cloud disk capacity quota varies based on the disk category. For information about how to view the capacity quotas, see the View or increase the general quotas of EBS resources section of the "Manage ECS quotas" topic. | |
The capacity of a basic disk | 5 GiB to 2,000 GiB | N/A |
The capacity of a standard SSD | 20 GiB to 32,768 GiB | N/A |
The capacity of an ultra disk | 20 GiB to 32,768 GiB | N/A |
The capacity of an Enterprise SSD (ESSD) |
| N/A |
The capacity of an ESSD AutoPL disk | 1 GiB to 65,536 GiB | N/A |
The capacity of an ESSD Entry disk | 10 GiB to 32,768 GiB | N/A |
The capacity of a Regional ESSD | 1 GiB to 65,536 GiB | N/A |
The capacity of a local SSD | 5 GiB to 800 GiB | N/A |
The capacity of all local SSDs per instance | 1,024 GiB | N/A |
The capacity of an elastic ephemeral disk | 64 GiB to 8,192 GiB | N/A |
The capacity of a system disk |
Note Basic disks are the previous generation of disks that are unavailable for purchase. If you use basic disks as system disks, the capacity of each basic disk is up to 500 GiB. | N/A |
Permissions to attach new local disks to instances equipped with local disks | You cannot attach new local disks to instances already equipped with local disks. | N/A |
Permissions to change the configurations of instances equipped with local disks | You can change only the bandwidth configurations of instances equipped with local disks. | N/A |
The mount point of the system disk on a Linux instance |
| N/A |
The mount points of the data disks on a Linux instance | The mount points are named based on the number of data disks:
| N/A |
The capacity of block storage devices is measured in binary units. The multiple of two neighboring binary units is 1,024. For example, 1 GiB equals 1,024 MiB.
For more information about block storage devices, see Overview of Block Storage.
Snapshots
Item | Limit | Method to raise limits |
The maximum number of manual snapshots that can be retained per cloud disk | 256 | N/A |
The maximum number of automatic snapshots that can be retained per cloud disk | 1,000 | N/A |
The maximum number of automatic snapshot policies that can be retained in an Alibaba Cloud account per region | 100 | N/A |
The number of automatic snapshot policies that you can associate with a cloud disk | 1 | N/A |
The number of snapshots that can be concurrently created per cloud disk | 1 | N/A |
The categories of block storage devices that support snapshots |
| N/A |
Download or export of snapshots | You cannot download or export created snapshots. You can create custom images from snapshots and export the custom images to your on-premises device. | N/A |
Limits on manual and automatic snapshot creation |
| N/A |
For more information about snapshots, see Overview.
SSH key pairs
Item | Limit | Method to raise limits |
The maximum number of SSH key pairs that an Alibaba Cloud account can retain per region | 500 | N/A |
Images that support SSH key pairs | Only Linux images. | N/A |
For more information about SSH key pairs, see Manage SSH key pairs.
Public bandwidth
This section describes the total maximum bandwidth of all pay-as-you-go and preemptible instances that use the pay-by-bandwidth billing method for network usage within an Alibaba Cloud account per region.
NoteYou can view and increase the quota based on the quota ID
q_internet-bandwidth-pay-by-bandwidth-of-postpaid-instance
. For more information, see the View or increase the general quotas of ECS resources section of the "Manage ECS quotas" topic.Region
Limit
China (Beijing), China (Shanghai), China (Hangzhou), and China (Shenzhen)
50 Gbit/s
China (Hong Kong) and Singapore
20 Gbit/s
Others
10 Gbit/s
As of November 27, 2020, the available maximum bandwidth when you create ECS instances or change their configurations is subject to the throttling policy of your account.
NoteTo increase the maximum bandwidth, submit a ticket.
In each region, the total maximum bandwidth of all ECS instances that use the pay-by-traffic billing method for network usage within an Alibaba Cloud account cannot exceed 5 Gbit/s.
In each region, the total maximum bandwidth of all ECS instances that use the pay-by-bandwidth billing method for network usage within an Alibaba Cloud account cannot exceed 50 Gbit/s.
Limits on the maximum bandwidth per instance and changes to the public IP address of an instance:
ImportantIf you use the pay-by-traffic billing method for network usage, the maximum inbound and outbound bandwidths are used as the upper limits instead of guaranteed performance specifications. In scenarios in which demand exceeds resource supplies, the maximum bandwidths may not be reached. If you want guaranteed bandwidths for your ECS instances, use the pay-by-bandwidth billing method for network usage.
Item
Limit
Method to raise limits
The maximum inbound bandwidth per instance
If the purchased maximum outbound bandwidth is less than or equal to 10 Mbit/s, Alibaba Cloud allocates an inbound bandwidth of 10 Mbit/s.
If the purchased maximum outbound bandwidth is greater than 10 Mbit/s, Alibaba Cloud allocates an inbound bandwidth that is equal to the purchased maximum outbound bandwidth.
N/A
The maximum outbound bandwidth per instance
Pay-by-traffic:
Subscription instance: 200 Mbit/s
Pay-as-you-go instance: 100 Mbit/s
Pay-by-bandwidth: 200 Mbit/s
N/A
Changes to the assigned public IP address of an instance
The public IP address of an instance can be changed within 6 hours after the instance is created and can be changed up to three times.
N/A
The maximum public bandwidth of an ECS instance is limited to the network baseline bandwidth of the instance type. For more information, see Overview of instance families.
For more information about public bandwidth, see the Public bandwidth section of the "Network bandwidth" topic.
ENIs
Item | Limit | Method to raise limits |
The maximum number of secondary elastic network interfaces (ENIs) that can be created for an Alibaba Cloud account per region | You can view the quota based on the quota ID | |
Virtual private cloud (VPC) and zone | An ECS instance and the ENIs bound to the instance must reside in the same VPC and zone.
| N/A |
The maximum number of ENIs per instance | The number of ENIs you can bind to an ECS instance varies based on the instance type. For more information, see the ENIs columns in Overview of instance families. | N/A |
For more information about ENIs, see Overview.
Prefix lists
Item | Limit | Method to raise limits |
The maximum number of prefix lists allowed for an Alibaba Cloud account per region | 100 | N/A |
The maximum number of entries in a prefix list | 200 | N/A |
The maximum number of resources that can be associated with a prefix list | 1,000 | N/A |
For more information about prefix lists, see Overview.
Port lists
Item | Limit | Method to raise limits |
The maximum number of port lists allowed for an Alibaba Cloud account per region | 1,000 | N/A |
The maximum number of entries in a port list | 2,000 | N/A |
The maximum number of resources that can be associated with a port list | 1,000 | N/A |
For more information about port lists, see Overview.
Security groups
Item | Limit on basic security groups | Limit on advanced security groups |
The maximum number of security groups allowed for an Alibaba Cloud account per region | You can view the quota or apply for a quota increase based on the quota ID | The limit is the same as the limit on basic security groups. |
The maximum number of ECS instances of the classic network type that a security group of the classic network type can contain | 1,000 Note If more than 1,000 instances of the classic network type require mutual access over the internal network, you can assign the instances to multiple security groups and allow mutual access among the security groups. | Advanced security groups do not support the classic network. |
The maximum number of ECS instances of the VPC type that a security group of the VPC type can contain | This limit varies based on the number of private IP addresses that the security group can contain. | No limit. |
The maximum number of security groups that can be associated with an ECS instance | 10 | The limit is the same as the limit on basic security groups. |
The maximum number of security groups that can be associated with an ENI bound to an ECS instance | ||
The maximum number of inbound and outbound rules in all security groups associated with an ENI | 1,000 | The limit is the same as the limit on basic security groups. |
The maximum number of rules that reference security groups as authorization objects (sources or destinations) in a security group | 20 | 0. You cannot add rules that reference security groups as authorization objects (sources or destinations) to an advanced security group or reference advanced security groups as authorization objects (sources or destinations) in security group rules. |
The maximum number of private IP addresses that a security group of the VPC type can contain within an Alibaba Cloud account per region | 6,000 Note
| 65,536 |
Internet access port | For security reasons, port 25 is disabled on ECS instances by default. We recommend that you use the SSL port to send emails. In most cases, the SSL port is port 465. | The limit is the same as the limit on basic security groups. |
For more information about security groups, see Overview.
Reserved instances
Item | Limit | Method to raise limits |
The total number of regional reserved instances allowed for an Alibaba Cloud account in all regions | 20 | |
The maximum number of zonal reserved instances allowed for an Alibaba Cloud account per zone | 20 | |
Instance type | The gn6i and t5 instance families do not support regional reserved instances. You cannot split or merge gn6i or t5 reserved instances. Note The instance types that you can select when you purchase a reserved instance are displayed on the buy page. | N/A |
Eligible resources |
| N/A |
For more information about reserved instances, see What is a reserved instance?
Savings plans
Item | Limit | Method to raise limits |
The maximum number of savings plans that you can purchase by using an Alibaba Cloud account | 200 | N/A |
Eligible resources |
| N/A |
For more information about savings plans, see What is a savings plan?
SCUs
Item | Limit | Method to raise limits |
The maximum capacity that you can purchase for a storage capacity unit (SCU) | 50 TiB | |
The maximum number of SCUs that you can purchase per region | 100 | N/A |
Resource types that support SCUs |
| N/A |
Eligible resources | SCUs can be used to offset only the fees for pay-as-you-go resources, but not for pay-as-you-go disks attached to preemptible instances. | N/A |
Effective time | You can configure an effective time for each SCU. The effective time can be up to six months from the creation time of the SCU. | N/A |
Creation and management of SCUs by calling API operations | Not supported. | N/A |
For more information, see SCUs.
Launch templates
Item | Limit | Method to raise limits |
The maximum number of launch templates allowed for an Alibaba Cloud account per region | You can view the quota based on the quota ID | |
The maximum number of versions in a launch template allowed for an Alibaba Cloud account per region | You can view the quota based on the quota ID | |
Launch template parameters | When you create a launch template, all parameters are optional. However, if a launch template does not include required parameters, such as the instance type and image, you must specify the parameters when you use the template to create ECS instances. | N/A |
Launch template modification | After you create a launch template, you cannot modify the template. You can create a new version of the launch template and modify the parameters of the new version. For more information, see Manage launch template versions. | N/A |
For more information about launch templates, see Overview.
Deployment sets
Item | Limit | Method to raise limits |
The maximum number of deployment sets allowed for an Alibaba Cloud account per region | You can view the quota based on the quota ID | |
The maximum number of ECS instances per deployment set | The maximum number of ECS instances in a deployment set varies based on the deployment strategy. For more information, see the Deployment strategies section of the "Deployment set" topic. | N/A |
Dedicated host creation in deployment sets | Dedicated hosts cannot be created in deployment sets. | N/A |
Region and zone | ECS instances and the deployment set to which the instances belong must reside in the same region. ECS instances in a deployment set that uses the low latency strategy must be deployed in the same zone. | N/A |
Instance types and families supported by a deployment set | The instance types and families supported by a deployment set vary based on the deployment strategy. You can call the DescribeDeploymentSetSupportedInstanceTypeFamily operation to query the instance types and families supported by each deployment strategy. | N/A |
Deployment set merging | Deployment sets cannot be merged. | N/A |
For more information, see Deployment set.
Auto provisioning groups
Item | Limit | Method to raise limits |
Cross-region instance provisioning | Auto provisioning groups cannot provision instances across regions. | N/A |
The maximum number of configuration sources that you can specify for an auto provisioning group | For each auto provisioning group, you can specify only one version of a launch template as the basic configuration of instances. However, you can specify multiple resource pools to extend the available instance types. | N/A |
The maximum number of resource pools that you can specify for an auto provisioning group | An auto provisioning group supports up to 20 resource pools, each consisting of a zone and multiple instance types. | N/A |
The maximum number of ECS instances that can be created by an auto provisioning group | 1,000 | N/A |
For more information about auto provisioning groups, see Overview.
Cloud Assistant
Item | Limit | Method to raise limits |
The maximum number of Cloud Assistant commands within an Alibaba Cloud account per region | You can view the quota based on the quota ID | |
The maximum size of the output for a Cloud Assistant command task within an Alibaba Cloud account per region | You can view the quota based on the quota ID | N/A |
The retention period of the output for a Cloud Assistant command task within an Alibaba Cloud account per region | You can view the quota based on the quota ID | N/A |
The maximum number of registration codes for Cloud Assistant managed instances within an Alibaba Cloud account per region | You can view the quota based on the quota ID | N/A |
The maximum number of ECS instances on which you can concurrently run a Cloud Assistant command within an Alibaba Cloud account per region | You can view the quota based on the quota ID | |
The size limits on files that consist of batch, PowerShell, or shell scripts with custom parameters after the files are Base64 encoded |
| N/A |
The maximum number of custom parameters in a command | 20 | N/A |
Operating system | You can run Cloud Assistant commands only on instances that use the following operating systems:
Note
| N/A |
For more information about Cloud Assistant, see Overview.
API operations
Item | Limit | Method to raise limits |
Rates of ECS API operations | API rate quotas limit the rates at which you can call API operations. The quotas are classified into the following categories based on the API version and resource type:
|
|
For more information about ECS API operations, see Integration overview.