Unable to use snapshot

This article is for Zmanda Recovery Manager For MySQL (ZRM) 

Error Message

BackupSet1:backup:WARNING: Snapshot failed
BackupSet1:backup:WARNING: Could not read file /tmp/jVLTspNpUs
BackupSet1:backup:WARNING: Unable to use snapshot

Error Description

Error occurs due to some problem during snapshot creation. It may be because if no free physical extents available or due to some other reason.

Solution

To find out the exact reason for failing of snapshot run the following command as mysql user.

#mysql-zrm-backup --backup-set <YourBackupSetName> --lvm-snapshot
<size> --verbose --backup-mode raw

eg.

mysql-zrm-backup --backup-set BackupSet1 --lvm-snapshot
10M --verbose --backup-mode raw

The command will do the backup using snapshot and logging will be verbose.
You can find the exact cause of failure of snapshot from the output above command.