My Environment:

  • ESXi 5.5 u2
  • vCenter 5.5 u2
  • only 1 VSAN datastore in cluster
  • 2 cluster in vCenter

Symptoms:

  • Cannot perform snapshot consolidation in VMware ESXi 5.5
  • Performing a snapshot consolidation in ESXi 5.5 fails.

Screenshot_2aScreenshot_1 Screenshot_2Screenshot_5Screenshot_3Screenshot_6 Screenshot_7 Screenshot_8 Screenshot_8a Screenshot_9 Screenshot_10

In logs on this VM (vmware.log) we found:



2016-05-04T20:03:57.420Z| vcpu-0| I120: DISKLIB-LIB   : Free disk space is less than imprecise space neeeded for combine (0x1fbd3800 < 0xd3714800, in sectors). Getting pre
cise space needed for combine...
2016-05-04T20:04:10.494Z| vcpu-0| I120: SnapshotVMXConsolidateHelperProgress: Stunned for 13 secs (max = 12 secs). Aborting consolidate.
2016-05-04T20:04:10.494Z| vcpu-0| I120: DISKLIB-LIB   :DiskLibSpaceNeededForCombineInt: Cancelling space needed for combine calculation
2016-05-04T20:04:10.495Z| vcpu-0| I120: DISKLIB-LIB   : DiskLib_SpaceNeededForCombine: failed to get space for combine operation: Operation was canceled (33).
2016-05-04T20:04:10.495Z| vcpu-0| I120: DISKLIB-LIB   : Combine: Failed to get (precise) space requirements.
2016-05-04T20:04:10.495Z| vcpu-0| I120: DISKLIB-LIB   : Failed to combine : Operation was canceled (33).
2016-05-04T20:04:10.495Z| vcpu-0| I120: SNAPSHOT: SnapshotCombineDisks: Failed to combine: Operation was canceled (33).

After fast troubleshooting with VMware engineer we receive summary:

“I tracked down that KB I mentioned, and it’s somewhat related but it also seems to be related to a newer VSAN-specific bug.

I mentioned this calculation that must be done in certain cases.

When a consolidation is called, the host does a basic check – is the snapshot file larger than the amount of free space on the datastore. If there is definitely enough free space, itt proceeds with the consolidation.

However, if the snapshot file is larger than the amount of free space then we need to do a more detailed calculation to determine if we will be able to consolidate without filling up the datastore.

We allow 12 seconds to perform this calculation – if it takes any longer, then we abort the consolidation.

This is exactly what we see in your logs.

As we saw, there is more than enough free space on the VSAN datastore

Screenshot_9_datastore

so we should not need to be doing this precise calculation. I’ve found a bug in VSAN where there is a problem with the calculation, meaning that consolidation may fail for VMs with large snapshot files:

https://kb.vmware.com/kb/2118663

We don’t see the exact symptoms here – your consolidation is not failing with ‘insufficient space’, it is failing with ‘operation was cancelled’. But it seems to be related to the same root cause.

The fix for the problem went into 5.5U3b so obviously that is not an option right now.

As far as I know, the workaround mentioned in the KB may also not be an option as I don’t think you would have a suitable datastore to send the clone to.

However, there is another workaround which has helped some other customers:

  • – Shut down the virtual machine
  • – Right-click the virtual machine and click Edit Settings.
  • – Click the Options tab.
  • – Under Advanced, click General.
  • – Click Configuration Parameters and add snapshot.maxConsolidateTime = 120

  This should allow more time for the calculation to complete and may allow consolidation to proceed.”

After this investigation i additional KB which can confirm this way of working:

VMware KB:    Snapshot consolidation in VMware ESXi 5.5.x and ESXi 6.0.x  fails with the error: maximum consolidate ret…

Resolution:

I belive is many ways to remove “Virtual machine Consolidation is needed” warning but in my case that way was that working way. After some preparation we shutdown VM and add advanced parameter to VM

snapshot.maxConsolidateTime = 120

Screenshot_12

and start VM again. Next manually performed consolidation with success.

Screenshot_3

Sources:

I hope this informative for you. Thanks for Reading!.  Be Social and share it in social media, if you feel worth sharing it. Please comment if you have some own experience related with this topic.

Leave a Reply