VM backups are failing sporadically with the following error message:
Apr 07, 2014 02:26:01 PM Operation with the Virtual Machine "test" is started Apr 07, 2014 02:26:01 PM Backing up environment test to pcsc01sn01 Apr 07, 2014 02:26:01 PM Adjusting backup type (full) Apr 07, 2014 02:26:02 PM Operation with the Virtual Machine "test" is finished with errors: Can't backup VM. Unable to perform the action because the virtual machine is busy. The virtual machine is being backed up. Please try again later. Failed Apr 07, 2014 02:26:02 PM Completing the process Failed
The number of VMs on the server is large (up to >40 VMs).
- The backups work fine for some time after restarting Parallels Dispather Service (
The issue is recognized as a product bug with internal ID PSBM-26171:
prl_backup_client sometimes fails to create a backup under big loads due to high number of file descriptors.
The permanent fix is included in Parallels Cloud Server 6.0 Update 7 (6.0.7-2195).
The immediate workaround is to restart the service by killing it forcibly (this way VMs are not getting interrupted):
# kill -9 `pidof prl_disp_service`