Vmware consolidating snapshots
Occasionally we saw where a snapshot commit/delete operation request would not merge the snapshot delta files with the VMs base disk (what we term a consolidate operation).Unfortunately, this failure to consolidate was not apparent via the UI, and usually only became noticeable to the end user when the delta files grew very large, possibly resulting in a full VMFS or NFS volume if they were attached to very large VMs.After consolidation, redundant disks are removed, which improves virtual machine performance and saves storage space.The presence of redundant delta disks can adversely affect virtual machine performance.
The Needs Consolidation column in the v Sphere Client shows the virtual machines that need to be consolidated and the virtual machine's tab shows a Configuration Issues consolidation message if the virtual machine needs to be consolidated.
If the consolidation fails, there were no snapshots shown in the Snapshot Manager, but the snapshot files were still being used on the datastore. Unfortunately today this happened for me too, but it has been the first time this happened in a v Sphere 5 environment.
And therefore it was also the first time I noticed a new feature in VMware v Sphere 5 / v Center 5: “consolidate snapshots”.
Committing a snapshot on a VM fails and you can’t get your VM to boot again because there are disks missing.
This could happen because when initiating Delete or Delete All snapshots, the snapshot details are deleted from Snapshot Manager, then the snapshot files are consolidated and merged to another snapshot file or to the virtual machine parent disk.