There are certain prerequisites for MySQL backups, which should be looked into by a qualified database and/or system administrator. Failure to do so may result in invalid or incomplete MySQL backups. Here are some primary examples:
- Disk space - Depending on where MySQL is being backed up, it is very important that there is enough free disk space to ensure a full backup can be taken.
- InnoDB corruption - If InnoDB corruption is occurring, attempting to back up MySQL databases may result in further corruption and very likely unusable backups. This issue must be properly resolved prior to backing up MySQL to ensure MySQL does not fail upon subsequent upgrades or restarts.
- Filesystem issues - If the filesystem is reporting issues, a consistency check or repair should be done prior to backing up MySQL. Generating partially corrupted MySQL backups is a possibility.
- Unstable server - Servers that are not stable and prone to crashing should first ensure the underlying issue be investigated and fixed before backing up MySQL. A system crash during a backup process may result in an unusable backup.