Deleting Snapshot

[hughslh]

Hi Guys. I'm new to VSphere. I've just completed VMware vSphere Install, configure manage v6.7 training.

So here's my question. It turns out one of the admins created a snapshot a year ago of one of our servers. This server is critical to patient treatment. If I delete the snapshot is there a way to estimate how long the consolidation of data might take and what, if any, performance issue might occur?

[MikeStoica]

How big is the machine? Deleting the performance will affect VM performance during that period of time.

[HassanAlKak88]

Hello,

It is recommended to delete old snapshots because the presence of redundant delta disks can adversely affect virtual machine performance.

The consolidation time depend on the size, performance of host (resources) and the storage IOPS.

Yes it is recommend to delete the snapshot after working hours due to some performance influence for this VM.

And check the following to work with snapshots:  Delete a Snapshot in the vSphere Web Client

Please consider marking this answer "CORRECT" or "Helpful" if you think your question have been answered correctly.

Cheers,

VCIX6-NV|VCP-NV|VCP-DC|

@KakHassan

linkedin.com/in/hassanalkak

[hughslh]

Thanks for the quick response guys.

The snapshot was created a year ago and now at  566 GB. It seems it was created by Veeam when running a backup but for some reason Veeam was unable to remove the snapshot when the backup completed.

[IRIX201110141]

I often take a look to esxtop first and check the Writes MB/s for the gives storage device/hba to get an baseline. Than click the "delete all Snapshot" and check esxtop again. With the CMDs or better Writes MB/s and the Snapshot size i can calculate the time based on XXGB/h.

Regards,

Joerg

[a_p_]

Welcome to the Community,

as already mentioned by others, the time required to delete the snapshot depends on the underlying storage.

Anyway, what's even more important is whether there's enough free disk space on the datastore to safely delete the datastore. Depending on the virtual disk's provisioning type (thin, or thick), deleting the snapshot may increase the base/flat .vmdk file, i.e. may temporarily require free disk space.

How is the VM's virtual disk provisioned, and how much free disk space do you currently have on the datastore?

André

[hughslh]

Hi Àndre. There is acres of free space on the data stores. There are 5 disks connected to this server - 40 GB - 200 GB - 40 GB - 30 GB - 256 GB.

[a_p_]

With sufficient free disk space, and assuming that you are not running a high performance database, or application on this VM, I actually wouldn't expect any issues with deleting the snapshots. I can't tell you how long it will take, but I'd expect that it won't take more than 3-4 hours.

What you may want to make sure is:

• you have an up-to-date backup
• make sure that backup doesn't kick in while the snapshot deletion is in progress
• schedule snapshot deletion for non-peak hours (as a best practice)

Unless there's a reason not to do this, select the Delete All Snapshot option from the Snapshot Manager.

André

[hughslh]

We do run a critical patient treatment system on this particular server. Whats the likelihood the consolidation could run into days?

[a_p_]

I really don't think it will take that long. I just recently had to cleanup a customer environment where one of the VMs ran on more than 200! snapshots with a total size of ~5TB, and IIRC it took less than a day to delete the snapshots (on local storage).

What kind of storage do you use?

• local or shared storage
• if local - what type/model of controller, how much write-cache, hao many disks, which RAID level?
• if shared - iSCSI, Fiber-Channel, or NAS, which connection speed, which storage type/model

André

[hughslh]

We are using shared iSCSI with top stack SSD and bottom stack 15K. Its a new Dell unity kit so its a pretty good spec. I have spoken with patient treatment centre and we have decided to do it this evening because there is no treatment planned over the weekend. I'll keep you posted on the results. Many thanks for all your help.

[a_p_ · Accepted solution]

Since you mentioned SSDs, I guess that you are using a 10gbps iSCSI connection, so the deletion should run pretty fast with the Unity as the storage system.. Even with a 1 gbps connection, it shouldn't take longer than the mentioned 3-4 hours.

Please consider to pause the Veeam backup job for this VM, to ensure it doesn't start while the deletion is in progress.

André

[hughslh]

Many thanks for all the help guys. We deleted the snapshot out of peak hours and the consolidation took only 1 hour.