Snapshot of MariaDB Add-on likely corrupt

[stewartsmith]

The problem

When creating a Snapshot to download from the HA Web UI, the MariaDB portion is just a copy of the data directory. Seeing as this is not done with mysqldump or 'xtrabackup`, it means that writes may be ongoing as the files are copied, which render the copy corrupt.

i.e. by default, the 'snapshot' cannot be consistent for the MariaDB database.

Environment

Applies to all environments.

• Add-on with the issue: MariaDB
• Add-on release with the issue: All
• Last working add-on release (if known): Never
• Operating environment (OS/Supervised): All

Problem-relevant configuration

recorder:
  db_url: mysql://homeassistant:XXXXXXX@core-mariadb/homeassistant?charset=utf8
  

Traceback/Error logs

Additional information

The correct behaviour should be that when you create a Snapshot of the MariaDB database, it either uses mysqldump or xtrabackup to create a consistent copy of the data. Anyone currently successfully using the snapshot to restore a MariaDB database is getting a non-corrupt database purely by accident.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[jrial]

Does this still happen?

[oncleben31]

It happened to me yesterday

[svh1985]

One option would be to quickly stop MariaDB before the backup or restore. I used that trick when a restore did not work due to corrupt data.

[stewartsmith]

Stopping/Starting MariaDB before/after backup is more of a workaround, and does cause an outage. The mysqldump utility that ships with it can get a logical (SQL) backup that's consistent without a problem and not have downtime.

[oncleben31]

@stewartsmith Have you an example of implementation of this ?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[jrial]

Unstale.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[xzwr]

Still not solved.

[Delta1977]

Still open. At Moment Mariadb-Addon Snapshots / Backup is unusable.
This should be resolved as other Addons like "Home Assistant Community Add-on: Nginx Proxy Manager" depends on mariadb

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stewartsmith]

It doesn't look like anything has changed. The backup tarballs still contain a copy of the MariaDB data directory, and unless there's extra XtraBackup steps being performed behind the scenes, then this is still basically just a corrupt copy of the database as part of the "backup"

[ludeeus]

There is, it was implemented in #2063