Extreme NAS file systems support the snapshot feature. You can use this feature to restore data across zones. Before you perform high-risk operations, you can create snapshots to back up data. If your data is lost, you can restore some or all of the data in a file system from a snapshot to a specified point in time. If a file system in a zone is unavailable, you can restore the data in the file system from a snapshot of the file system to another zone. This way, you can ensure service continuity. This topic describes how to manage snapshots for a file system in the Apsara File Storage NAS console. You can create snapshots, create snapshot policies, and apply snapshot policies.
Prerequisites
Usage notes
- You can manually create a maximum of 128 snapshots for each file system. A maximum of 128 snapshots can be automatically created for each file system.
- If a snapshot is being created for a file system, you cannot create another snapshot for the file system.
- If a file system expires when a snapshot is being created for the file system, the file system is released and the snapshot is deleted.
- When a snapshot is being created for a file system, the performance of the file system may be slightly compromised and the IOPS may be temporarily degraded. We recommend that you do not create snapshots during peak hours.
- A snapshot is a backup of a file system at a specific point in time. When you create a snapshot for a file system, incremental data of the file system is not synchronized to the snapshot.
Manually create a snapshot
- Manually created snapshots are permanently retained in a file system. We recommend that you delete the snapshots that you no longer need on a regular basis to reduce costs.
- Manually created snapshots are permanently retained only if your account has sufficient balance. If you can no longer use NAS for 15 days due to overdue payments, the snapshots that you manually created are deleted.
Create an automatic snapshot policy
- You can apply an automatic snapshot policy to multiple file systems.
- If the number of snapshots that are automatically created for a file system reaches 128, the file system deletes the earliest snapshot. Manually created snapshots are not affected.
- If you modify the retention period in an automatic snapshot policy, the new retention period applies only to new snapshots. The original retention period still applies to the existing snapshots.
- If a snapshot is being created when the scheduled time for a new snapshot arrives,
the creation of the new snapshot is skipped. This occurs if the file system stores
a large volume of data.
For example, you have scheduled snapshots to be automatically created at 09:00:00, 10:00:00, 11:00:00, and 12:00:00. The system starts to create a snapshot at 09:00:00 and does not complete the process until 10:20:00. The process takes 80 minutes because the file system has a large volume of data. In this case, the system does not create a snapshot at 10:00:00, but creates a snapshot at 11:00:00.
- Snapshots that are automatically created are named in the auto_yyyyMMdd_X format.
For example, auto_20140418_1 indicates the name of the first snapshot that was automatically created on April 18, 2014. In the preceding format, auto indicates that the snapshot is automatically created rather than manually created. yyyyMMdd indicates the date when a snapshot is automatically created. yyyy stands for the year, MM the month, and dd the day of the month. X indicates the ordinal number of the snapshot.
- Log on to the NAS console.
- In the left-side navigation pane, choose .
- Create an automatic snapshot policy.
- Apply the automatic snapshot policy.
Use a snapshot to create a file system
Related operations
Operation | Description |
---|---|
Cancel an automatic snapshot policy | To cancel an automatic snapshot policy, perform the following steps:
|
View a snapshot | On the Snapshot tab, view the list of snapshots and the details of each snapshot. |
Delete a snapshot | On the Snapshot tab, find the snapshot and click Delete. |
View automatic snapshot policies | On the Automatic Snapshot Policy tab, view the list of automatic snapshot policies and the details of each policy. |
View the file systems to which an automatic snapshot policy is applied | On the Automatic Snapshot Policy tab, find the automatic snapshot policy and click Apply to The File System to view the file systems to which the policy is applied. |
Modify an automatic snapshot policy | On the Automatic Snapshot Policy tab, find the automatic snapshot policy and click Modify Policy. |
Delete an automatic snapshot policy | On the Automatic Snapshot Policy tab, find the automatic snapshot policy and click Delete. |