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Friday, May 20, 2011

Error: 3941--VMware Data Recovery backup fails


VMware Data Recovery backup fails with the error: Failed to create snapshot. Error: 3941

Symptoms

  • Creation of a Snapshot of a VM fails.
  • If using Snapshots to facilitate backups, clones, etc, the other task also fails.
  • If using VDR, manifests as the error:

    Failed to create snapshot for "VMNAME" - error 3941 (create snapshot failed)
  • Manual quiesce snapshot fails with the error:

    A snapshot operation cannot be performed
  • In the vmware.log file of the virtual machine, you see error similar to:

    Oct 01 06:06:08.347: vmx| DISKLIB-LIB : Resuming change tracking.
    Oct 01 06:06:08.355: vmx| FILE: File_VMFSSupportsFileSize: Requested file size (554051831808) larger than maximum supported filesystem file size (274877906944)
    Oct 01 06:06:08.355: vmx| DiskLibCreateCustom: if your disk is on VMFS, you may consider increasing the block size.
    Oct 01 06:06:08.355: vmx| DISKLIB-LIB : Failed to create link: The destination file system does not support large files (12)
    Oct 01 06:06:08.355: vmx| SNAPSHOT: BranchDisk: Failed to create child disk '/vmfs/volumes/4b7d5904-ff90f633-7345-a4badb09bd7f /svsql01.ttni.com.sg/svsql01.ttni.com.sg_1-000001.vmdk' : The destination file system does not support large files (12)
    Oct 01 06:06:08.355: vmx| DISKLIB-VMFS : "/vmfs/volumes/4b82e7df-198a6606-f37c-a4badb09bd7f/svsql01.ttni.com.sg/svsql01.ttni.com.sg_1-flat.vmdk" : closed.
    Oct 01 06:06:08.355: vmx| SNAPSHOT: SnapshotBranch: Unlinking '/vmfs/volumes/4b7d5904-ff90f633-7345-a4badb09bd7f/svsql01.ttni.com.sg/svsql01.ttni.com.sg-000001.vmdk'.
    Oct 01 06:06:08.355: vmx| DISKLIB-VMFS : "/vmfs/volumes/4b7d5904-ff90f633-7345-a4badb09bd7f/svsql01.ttni.com.sg/svsql01.ttni.com.sg-000001-delta.vmdk" : open successful (17) size = 137438953472, hd = 0. Type 8
    Oct 01 06:06:08.355: vmx| DISKLIB-LIB : Resuming change tracking.
    Oct 01 06:06:08.358: vmx| DISKLIB-VMFS : "/vmfs/volumes/4b7d5904-ff90f633-7345-a4badb09bd7f/svsql01.ttni.com.sg/svsql01.ttni.com.sg-000001-delta.vmdk" : closed.
    Oct 01 06:06:08.360: vmx| SNAPSHOT: SnapshotBranch failed: The destination file system does not support large files (5).
    Oct 01 06:06:08.360: vmx| CPT current = 2, requesting 6
    Oct 01 06:06:08.360: vmx| Checkpoint_Unstun: vm stopped for 1287944 us
    Oct 01 06:06:08.360: vmx| SnapshotVMX done with snapshot 'test': 0
    Oct 01 06:06:08.360: vmx| Msg_Reset:
    Oct 01 06:06:08.360: vmx| [msg.checkpoint.save.fail2.std3] Error encountered while saving snapshot.
    Oct 01 06:06:08.360: vmx| The destination file system does not support large files.----------------------------------------
    Oct 01 06:06:08.360: vmx| Vix: [7370 vmxCommands.c:2353]: VMAutomationCreateSnapshotCallback: Got CreateSnapshot callback, snapshotErr = 12, UID = 0

Resolution

This issue may occur if the size of the snapshot file is larger than the available space on the datastore. In this case, the ESX host cancels the operation and displays the error.
 
To resolve this issue, compare the base disk size of the virtual machine with the block size of the datastore which contains the working directory of the virtual machine.
 
If the base disk size of the virtual machine is larger than the block size of the datastore, try one of these options: 
Note: This issue can also occur if you do not have the correct vCenter permissions to take a snapshot. Verify the permissions for your account if you see this error.