Symptom
A VM backup fails and presents the following error code:
Error Code 91:26 Unable to create a Virtual Machine snapshot of [].
Cause
The snapshot exceeds the maximum file size for the server.
The following message is shown in the JobManager.log file on the CommServe:
30368 75c4 10/30 14:15:33 1188013 Servant [---- IMMEDIATE BACKUP REQUEST ----], taskid [21876] Clnt[...] AppType[Virtual Server][106] BkpSet[Initial VM Test] SubClnt[Single VM Test (Only) -VC02] BkpLevel[Full][1]
30368 81e8 10/30 14:17:18 1188013 Scheduler Set pending cause [Unable to create a Virtual Machine snapshot of [...]. Please check the Virtual Machine snapshot tree. It may be necessary to upgrade/reinstall the VMware tools on the Virtual Machine. Please consult http://kb.vmware.com/kb/1009073 for additional information.]::Client [...] Application [vsbkp] Message Id [1526726682] RCID [0] ReservationId [0]. Level [0] flags [0] id [0] overwrite [0] append [0] CustId[0].
Review the vsbkp.log file located on the Virtual Server Agent Client.
Default Log location: C:\Program Files\CommVault\ContentStore\Log Files
5028 5 10/30 14:17:00 1188013 ### CreateSnapshot_Task --- Started Create Snapshot task task-2967 for VM [...] 5028 5 10/30 14:17:16 1188013 ### _WaitForTask --- Task [task-2967] status [error] waited for [00:00:15.4438020] task took [00:00:14.5466880] Wait [10/30/2012 2:17:00 PM to 10/30/2012 2:17:16 PM] Task [10/30/2012 2:17:00 PM to 10/30/2012 2:17:15 PM] 5028 5 10/30 14:17:16 1188013 ### CreateSnapshot_Task --- Failed to create Snapshot from VM [...] - File is larger than the maximum size supported by datastore ' 5028 eec 10/30 14:17:16 1188013 CVMWareInfo::_CreateVMSnapshot() - Unable to create snapshot of VM [...], trying without quiesing filesystem 5028 5 10/30 14:17:16 1188013 ### CreateSnapshot_Task --- Started Create Snapshot task task-2968 for VM [...] 5028 5 10/30 14:17:18 1188013 ### _WaitForTask --- Task [task-2968] status [error] waited for [00:00:02.1215728] task took [00:00:01.6874780] Wait [10/30/2012 2:17:16 PM to 10/30/2012 2:17:18 PM] Task [10/30/2012 2:17:16 PM to 10/30/2012 2:17:17 PM] 5028 5 10/30 14:17:18 1188013 ### CreateSnapshot_Task --- Failed to create Snapshot from VM [...] - File is larger than the maximum size supported by datastore ' 5028 eec 10/30 14:17:18 1188013 CVMWareInfo::_CreateVMSnapshot() - Failed to create Snapshot of VM [...] Guid [...]
Resolution
Check the virtual machine snapshot tree. It may be necessary to upgrade or reinstall the VMware tools on the virtual machine. For more information, see Unable to take a quiesced VMware snapshot of a virtual machine (1009073).
The error message "File is larger than the maximum size supported by datastore" is a VMware error; there is a VMware Knowledge Base article that covers the proper way to fix the issue:
Review and follow all steps in the VMware Knowledge Base article. Compare the base disk size of the VMDK or virtual-mode RDM of the virtual machine against the block size of the datastore that contains the working directory of the virtual machine.
By default, the working directory contains the virtual machine's .vmx configuration file. The maximum file size differs among versions of ESX and ESXi, and among versions of VMFS.