Consolidating snapshosts in vSphere 4.1
I stumbled in a nice article explaining the changes to the snapshot consolidation mechanism which was introduced in the vSphere U2. The article was posted in the VMware Support insider section here. The article is written by Simon Todd, who is a Tech Support Engineer in Cork, Ireland office.
One of the main troubles when consolidating snapshots is the free space on the datastore. You could easily run into situation when you had an error message saying that your datastore does not have enough free space.
If you don't have enough space on your datastore you won't be able to consolidate your snapshots. At least up to vSphere 4 U1. In vSphere U2 the new way of consolidating snapshot was introduced and now the process it's not only faster, but also less demanding on free space on the datastore.
A quick quote from the blog:
As of vSphere 4.0 Update 2 the snapshot consolidation operation has changed, instead of rolling the snapshots into each other, the snapshot process now takes the oldest snapshot and consolidates that into the base disk, removes the snapshot and then processes the next oldest snapshot and merges that into the base disk, so after each snapshot is consolidated into the base disk it is removed. This not only saves on required disk space, but it also performs better:
Source: VMware Support Insider blog.
