Use Limits on Cloud Disk
| Limit Type | Restrictions |
|---|---|
| Elastic cloud disk capability | The data disks purchased with the CVM are all elastic cloud disks, which can be unmounted from the CVM and remounted. |
| Cloud disk performance | I/O performance takes effect at the same time. For example, for a 1 TB SSD, the maximum random IOPS can reach 26,000, which means that both read and write IOPS can reach this value. At the same time, due to several performance limitations, I/O with a block size of 4 KB/8 KB can reach the maximum value of IOPS in this example, but I/O with a block size of 16 KB cannot reach the maximum value of IOPS (the throughput has reached the limit of 260 MB/s). |
| Max attachable elastic cloud disks per CVM | Up to 32 disks. |
| Max cloud disks that can be created at a time | Up to 50 disks. |
| Restrictions for cloud disk mounting on CVM | The CVM and cloud disk must be in the same availability zone. |
Use Limits on Snapshot
| Limit Type | Restrictions |
|---|---|
| Limits on the creation types of cloud disks by snapshot | Only the data disk snapshot can be used to create an elastic cloud disk, and the system disk snapshot can only be used to create a custom image. |
| Limits on the creation sizes of cloud disks by snapshot | The capacity of the cloud disk created using a snapshot should be greater than or equal to that of the cloud disk from which the snapshot originated. |
| Limits on snapshot rollback | A snapshot can only be rolled back to the source cloud disk from which the snapshot was created. If you want to create a cloud disk using an existing snapshot, see Creating Cloud Disks Using Snapshots. |
| Total snapshot capacity | No limit. |
| Snapshot quota per cloud disk | 1,000 snapshots. |
Use Limits on Scheduled Snapshot Policies
| Limit Type | Restrictions |
|---|---|
| Limits on cloud disks that can be bound to a scheduled snapshot policy | Only cloud disks in the same region as the scheduled snapshot policy can be bound. A maximum of 200 cloud disks can be bound. |