When using ECS, consider the following:
- ECS does not support virtual application installation or subsequent virtualization such as when using VMware. Currently, only ECS Bare Metal Instance and Super Computing Clusters supports virtualization.
- ECS does not support sound card applications.
- ECS does not support the installation of external hardware devices such as hardware dongles, USB drives, external hard drives, and the USB security keys issued by banks.
- ECS does not support SNAT and other IP packet address translation services. You can achieve this by using an external VPN or proxy.
- ECS does not support multicast protocol. If multicasting services are required, we recommend that you use unicast point-to-point method.
- Currently, Log Service does not support 32-bit Linux ECS instance. To know the regions that support Log Service, see Service endpoint. To know the server operating systems that support Log Service, see Overview.
Besides the preceding limit, the additional limits of ECS are mentioned in the following table.
ECS instances
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Permission to create instances | Complete real-name registration to create ECS instances in the mainland China regions | Not supported |
| Default quota of Pay-As-You-Go ECS instances (including preemptible instances) in all regions for one account | 10 | Open a ticket |
| Launch templates in each region for one account | 30 | Not supported |
| Versions of one launch template | 30 | Not supported |
| Conversion of the billing method from Pay-As-You-Go to Subscription | Not supported in the following instance types or type families:
|
Not supported |
| Default available instance types for creating Pay-As-You-Go ECS instances (New generation) | ecs.t1.small (1 vCPU core, 1 GiB) | Open a ticket |
| ecs.s1.small (1 vCPU core, 2 GiB) | ||
| ecs.s1.medium (1 vCPU core, 4 GiB) | ||
| ecs.s2.small (2 vCPU core, 2 GiB) | ||
| ecs.s2.large (2 vCPU core, 4 GiB) | ||
| ecs.s2.xlarge (2 vCPU core, 8 GiB) | ||
| ecs.s3.medium (4 vCPU core, 4 GiB) | ||
| ecs.s3.large (4 vCPU core, 8 GiB) | ||
| ecs.m1.medium (4 vCPU core, 16 GiB) | ||
| Default available instance types for creating Pay-As-You-Go ECS instances (Previous generation) | ecs.n1.tiny (1 vCPU core, 1 GiB) | Open a ticket |
| ecs.n1.small (1 vCPU core, 2 GiB) | ||
| ecs.n1.medium (2 vCPU core, 4 GiB) | ||
| ecs.n1.large (4 vCPU core, 8 GiB) | ||
| ecs.n2.small (1 vCPU core, 4 GiB) | ||
| ecs.n2.medium (4 vCPU core, 8 GiB) | ||
| ecs.n2.large (4 vCPU core, 16 GiB) | ||
| ecs.e3.small (1 vCPU core, 8 GiB) | ||
| ecs.e3.medium (2 vCPU core, 16 GiB) |
Block storage
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Permission to create Pay-As-You-Go cloud disks | Complete real-name registration to create cloud disks in the mainland China regions | Not supported |
| Quota of Pay-As-You-Go cloud disks in all regions for one account | Five times of the number of Pay-As-You-Go instances in all regions under one account | Open a ticket |
| Quota of system disks for one ECS instance | 1 | Not supported |
| Quota of data disks for one ECS instance | 16 (including cloud disks and Shared Block Storage) | Not supported |
| Multi-node attachment of shared block storage | 8 | Not supported |
| Quota of shared block storage in all regions for one account | 10 | Open a ticket |
| Capacity of one Basic Cloud Disk | 5 GiB ~ 2,000 GiB | Not supported |
| Capacity of one SSD Cloud Disk | 20 GiB ~ 32,768 GiB | Not supported |
| Capacity of one Ultra Cloud disk | 20 GiB ~ 32,768 GiB | Not supported |
| Capacity of one ephemeral SSD disk | 5 GiB ~ 800 GiB | Not supported |
| Capacity of ephemeral SSD disks on one ECS instance | 1,024 GiB | Not supported |
| Capacity of one NVMe SSD local disk | 1,456 GiB | Not supported |
| Capacity of NVMe SSD local disks on one ECS instance | 2,912 GiB | Not supported |
| Capacity of one SATA HDD local disk | 5,500 GiB | Not supported |
| Capacity of SATA HDD local disks on one ECS instance | 154,000 GiB | Not supported |
| Capacity of one SSD Shared Block Storage device | 32,768 GiB | Not supported |
| Capacity of SSD Shared Block Storage devices on one ECS instance | 128 TiB | Not supported |
| Capacity of one Ultra Shared Block Storage device | 32,768 GiB | Not supported |
| Capacity of Ultra Shared Block Storage devices on one ECS instance | 128 TiB | Not supported |
| Size limit of one system disk | Windows: 40 GiB − 500 GiB Linux (excluding CoreOS)+ FreeBSD: 20 GiB − 500 GiB CoreOS: 30 GiB − 500 GiB | Not supported |
| Size limit of one data disk | Basic Cloud Disk: 5 GiB − 2,000 GiB SSD Cloud Disk/Ultra Cloud Disk/SSD Shared Block Storage/Ultra Shared Block Storage: 20 GiB − 32,768 GiB Local disk: See Local disks. | Not supported |
| Attaching an independent local disk to an ECS instance with local disks | Not supported | Not supported |
| Configuration changes of an ECS instance with local disks | Only changes to public network bandwidth are permitted | Not supported |
| Mount point for system disks | /dev/xvda | Not supported |
| Mount points for data disks | /dev/xvd[b-z] | Not supported |
Snapshots
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Quota of snapshots | Number of elastic block storage devices * 64 | Not supported |
Images
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Quota of custom images in all regions for one account | 100 | Open a ticket |
| Quota of accounts to share one custom image | 100 | Open a ticket |
| Requirements of images for instance types | 32-bit images are not supported on an instance with 4 GiB or more RAM. | Not supported |
Key pairs
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Quota of key pairs in all regions for one account | 500 | Not supported |
| Instance types supporting key pairs | All instance types, except those non-I/O optimized instance types in Generation I | Not supported |
| Images supporting key pairs | Linux images only | Not supported |
Security groups
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Quota of ECS instances for one security group | 1,000 | Not supported |
| Quota of rules for one security groups | 100 | Not supported |
| Quota of security groups in all regions for one account | 100 |
Open a ticket |
| Quota of security groups for one ECS instances | 5 | Open a ticket |
| Port | Access to TCP Port 25, which is the default port for the STMP service, is denied. It cannot be allowed by adding a security group rule. | Open a ticket. For more information, see Apply to open TCP port 25 |
ENI
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Quota of ENI in one region for one account | 100 |
Open a ticket |
Tags
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Quota of tags for one ECS instance | 20 | Not supported |
API
| Item | Limit | Supply for higher configuration or unlock configuration rights |
|---|---|---|
| Invocation quota of CreateInstance | At most 200 times per minute | Open a ticket |
 |
Note |
| For more information about the limits for VPC, see Limits. |