Help Center/ Cloud Container Engine/ User Guide/ Cluster Backup/ Cluster Backup FAQs
Updated on 2026-06-18 GMT+08:00
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Cluster Backup FAQs

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How Do I Customize a Cron Expression When Creating a Backup Plan?

The backup period supports crontab expressions. You can specify either a fixed time (for example, 0 3 * * 1 indicates that the backup runs at 03:00 every Monday) or a fixed interval (for example, * */6 * * * indicates that the backup runs every 6 hours).

# ┌───────────── Minute (0 to 59)
# │ ┌───────────── Hour (0 to 23)
# │ │ ┌───────────── A day in a month (1 to 31)
# │ │ │ ┌───────────── Month (1 to 12)
# │ │ │ │ ┌───────────── A day in a week (0 to 6) (Sunday to Saturday)
# │ │ │ │ │
# │ │ │ │ │
# │ │ │ │ │
# * * * * *

Each field in a cron expression supports specific special characters. The table below describes these characters.

Table 1 Special characters

Character

Description

Example Value

,

Specifies separated values.

Entering 1,30 in the minute field triggers a backup at the 1st and 30th minutes.

*

Matches any value in a field.

Entering * in the minute field triggers a backup every minute.

-

Specifies a range.

Entering 8-10 in the hour field triggers a backup every hour from 08:00 to 10:00.

/

Triggers a backup at the start time and then at a fixed interval.

Entering */3 in the hour field triggers a backup every three hours starting at 00:00. Entering 1/5 in the day of month field triggers a backup every five days starting on the first day of the month.

How Do I Troubleshoot a Backup Record Deletion Failure "backup storage location xxx is currently in read-only mode"?

Symptom

Solution

Check the access mode of the backup repository. If the access mode is read-only, backup records cannot be deleted. To resolve this issue, run kubectl to change spec.accessMode to ReadWrite. Then, retry the deletion.

How Do I Troubleshoot a Backup Repository Unavailable Error "Backup store contains invalid top-level directories: [xxx]"?

Symptom

Solution

The root directory of the OBS bucket for the backup repository must contain only the restores and backups directories. Delete any other files or folders from the OBS bucket to restore the backup repository.

How Do I Troubleshoot a Restoration Failure "error executing PVAction for persistentvolumes/pvc-xxxx"?

Symptom

Solution

During cluster restoration from backup data, the PVC is restored successfully, but the associated PV fails to be restored. Consequently, the PVC remains in the pending (Waiting for binding) state. To resolve this issue, you need to manually delete the PVC and perform an immediate restoration again. If the PVC is not deleted before you re-perform an immediate restoration, orphaned storage volumes may remain. If this occurs, manually delete the PV, and go to the EVS console and delete the residual EVS disks to prevent resource leakage.

How Do I Troubleshoot a Backup/Restoration Record Stuck in the Deleting State?

Symptom

A backup or restoration record remains in the Deleting state for an extended period, and a deletion failure message is displayed.

Solutions

The backup/restoration file in the OBS bucket or the associated EVS disk snapshot failed to be deleted, preventing the record from transitioning to the Deleted state. To resolve this issue, manually delete the files in the OBS bucket of the backup repository and the associated EVS disk snapshots. Then, retry deleting the backup/restoration record.

  • Deleting a restoration record:

    A restoration record file is stored in the restores directory of the backup repository's OBS bucket. The file name matches the restoration record name. Delete the file directly from the OBS console.

  • Deleting a backup record:
    • A backup record file is stored in the backups directory of the backup repository's OBS bucket. The file name matches the backup record name. Delete the file directly from the OBS console.
    • To clear the EVS disk snapshots associated with the backup record, perform the following steps:
      1. Go to the OBS console and open the backups directory of the backup repository's bucket.
      2. Navigate to the backup file directory.
      3. Download the xxx-volumesnapshots.json.gz file.

      4. Decompress the file to obtain the JSON file. Use an editor to open the decompressed file. The providerSnapshotID field is the EVS snapshot ID.

      5. Use the snapshot ID to delete the snapshot from the EVS console.
Parent Topic: Cluster Backup