Unable to create a subscription backup on NFS storage: Undefined index PLESK_DEBUG

Symptoms

• A subscription backup fails with the following error message:

  PLESK_ERROR: Error:
  Undefined index: PLESK_DEBUG

• Server backups are performed successfully

• The DUMP_D variable in /etc/psa/psa.conf is configured to an NFS v3 storage

• Running flock to a file stored in the NFS storage fails with the following error:

  # ( flock -x 9 || exit 1; echo ‘1: Locking for 5 secs’; sleep 5; echo ‘1: Done’ ) 9> /backups/lock
  flock: 9: No locks available

  Where:

  – The folder /backups is configured as DUMP_D variable in /etc/psa/psa.conf file.

Cause

Resolution

Workaround

If update is not possible for some reason you may try the following