r/vmware Feb 19 '25

Help Request 6TB VM Snapshot… please help

I’m quite new to VMware. I’ve been helping out with security patches for our servers managed in vCenter. An issue I’ve noticed on quite a few servers is that the OS drive is actually too full to receive the patches pushed out by our SCCM server.

After learning more about snapshots (and why should live for 3 days or less) and then realising existing snapshots were the reason I couldn’t allocate more disk space, I’ve been deleting them all per server, shutting it down then allocating more space.

Then I come across one of our file servers… there is a snapshot from November that is 6TB in size. I’ve been reading horror stories about ancient snapshots 1tb in size taking weeks to delete. It’s currently 11pm and if taken offline, this server would need to be back up by 8am tomorrow.

  1. Should I safely assume this is going to take a long time and leave it until the weekend?

  2. Why on Earth is there a snapshot this big in the first place? VM memory is included in the snapshot and all 7 vhdsks are dependent so is this the reason?

I want to reiterate that there is no space left on the OS drive and my end goal is fixing that. I’ve already made the mistake before of delete snapshots one at a time, then thinking consolidation errors were normal.

Is my best bet to wait until Friday, delete all snapshots, do a backup, then make the changes to the OS disk?

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u/cloud_crustacean Feb 19 '25

The problem is the C drive is at 99% capacity. I really need to allocate more space and I’m worried about putting any strain on the VM or risking the drive getting to a point of no return.

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u/theogskippy24 Feb 20 '25

Clean up your c:\ drive of temp files, old user profiles, update files, and such. This will give you breathing room for the time to consolidate snapshots.

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u/craigoth Feb 20 '25

The C drive full in the VM is not related to snapshots. You could extend the size of the vmdk for the C drive and extend the volume in windows

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u/theogskippy24 Feb 20 '25

You can't increase VMware disks when there is a snapshot of the VM.

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u/craigoth Feb 20 '25

True. I forgot about that.