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Wajeeh
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Consolidate Snap Shot OR Delete the snapshot we don't need

Dear Experts,

We have a virtual machine Linux and we recently increased its vmdk to add more 10GB but before doing so we took a snapshot of the machine in powered off state. Now increasing space is done and now if I see the disk for this machine it shows me 35GB 'thick'

This is the only snap shot we have for this machine. If I right click on machine and go snapshot> I see there snapshot manager, take a snapshot, revert to current snapshot and last is consolidate.

If I go to snapshot manager I see the point where I am now and the last point which is marked as 'before increasing space', So, I need to click consolidate OR click on the old snapshot and delete to maintain current state of machine? How the two are different consolidate and deleting all ?

if disk is thick, I can still get rid of snapshots? Please see attached images

Thanks and waiting for response.

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admin
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So what I understand now is that consolidation option is to be used when below condition is true:

'snapshot disks fail to compress after Delete or Delete All' operation, other wise I should go for delete snapshot in normal condition, please correct me if I understood wrong?

Consolidation operation deletes all your "redundant" redo logs. But delete all operation deletes your snapshots and consolidate to a single disk.

Consolidation wont cause any change in the number of snapshots. But delete / delete all will actually delete the snapshots and the changes present in that snapshot will be written back to its parent disk. And also always delete snapshot operation is initiated with a consolidation operation.

Let me know if you need more clarification here.

The delta disks are created when ever a snapshot is taken ?

Yes.

I have a virtual vcenter server and it have one snap shot which we created when we were starting to build the vcenter, can I delete it while I am connected to vcenter server using Vsphere client.

Yes you can delete it. But since its vCenter, please make sure that you have enough space available in your datastore to perform a delete snapshot operation. The space requirements are neatly explained by Duncan Epping in his blog..
Snapshots, the revision - Yellow Bricks

You could see some more insight into snapshots at the "Related Posts' section in the bottom of the page.

Please post your query here, if you want any more help. Smiley Happy

~dGeorgey

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tomtom901
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Delete the snapshot if you want to keep the machine in it's current state. Some documentation about deleting snapshots:

vSphere 5.5 Documentation Center

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admin
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I need to click consolidate OR click on the old snapshot and delete to maintain current state of machine? How the two are different consolidate and deleting all ?

The presence of redundant delta disks can adversely affect virtual machine performance.
You can combine such disks without violating a data dependency. After consolidation, redundant disks are removed, which improves virtual machine performance and saves storage space.
Snapshot consolidation is useful when snapshot disks fail to compress after a Delete or Delete all operation. This might happen, for example, if you delete a snapshot but its associated disk does not commit back to the base disk.


Deleting snapshots involves large amounts of disk reads and writes, which can reduce virtual machine performance until consolidation is complete.
Consolidating snapshots removes redundant disks, which improves virtual machine performance and saves storage space.


if disk is thick, I can still get rid of snapshots? Please see attached images

Yes you can.

~dGeorgey

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Wajeeh
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Dear ~dGeorgey,

So what I understand now is that consolidation option is to be used when below condition is true:


'snapshot disks fail to compress after Delete or Delete All' operation, other wise I should go for delete snapshot in normal condition, please correct me if I understood wrong?

The delta disks are created when ever a snapshot is taken ?

Also please tell me if I have a virtual vcenter server and it have one snap shot which we created when we were starting to build the vcenter, can I delete it while I am connected to vcenter server using Vsphere client.

Kind Regards,

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admin
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So what I understand now is that consolidation option is to be used when below condition is true:

'snapshot disks fail to compress after Delete or Delete All' operation, other wise I should go for delete snapshot in normal condition, please correct me if I understood wrong?

Consolidation operation deletes all your "redundant" redo logs. But delete all operation deletes your snapshots and consolidate to a single disk.

Consolidation wont cause any change in the number of snapshots. But delete / delete all will actually delete the snapshots and the changes present in that snapshot will be written back to its parent disk. And also always delete snapshot operation is initiated with a consolidation operation.

Let me know if you need more clarification here.

The delta disks are created when ever a snapshot is taken ?

Yes.

I have a virtual vcenter server and it have one snap shot which we created when we were starting to build the vcenter, can I delete it while I am connected to vcenter server using Vsphere client.

Yes you can delete it. But since its vCenter, please make sure that you have enough space available in your datastore to perform a delete snapshot operation. The space requirements are neatly explained by Duncan Epping in his blog..
Snapshots, the revision - Yellow Bricks

You could see some more insight into snapshots at the "Related Posts' section in the bottom of the page.

Please post your query here, if you want any more help. Smiley Happy

~dGeorgey

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Wajeeh
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Hello,

- I am clear now for delta disks creation takes place when ever snapshot is created.

- For vCenter , yes, we do have enough space to perform delete snapshot operation, so we are safe on it and proceed

For 'delete all' and consolidation I am still confused, you are saying consolidation won't cause any changes in number of snapshots, then in end you mentioned that 'delete snapshot ' operation is initiated with a consolidation operation, sorry for asking again but since I am not clear I am asking

Wajeeh
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~dGeorgey,

Thanks for your explanation, I understand now your description when I also followed this link:

http://www.orionscache.com/2013/02/the-new-consolidate-snapshots-vmware-feature/

where they are saying sometimes removing snapshot does not work, and its resolution is to use this new menu item in 5.x version 'consolidation' to remove stubborn snapshots.

thanks for your help.

Just one thing, any other thing to consider before I remove snap shot of our virtual VCenter server ? I will doing this operation while I will be connected to it through vSphere client. I will face any disconnection ? OR the hosts in cluster will face any interruption with this ? I now already verified that there is enough space on data store.

Thanks,

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admin
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Just one thing,

No. I see too many questions here .. Smiley Happy JFF. Post here till you get the clarity.

any other thing to consider before I remove snap shot of our virtual vCenter server ?

As long as you have enough storage, nothing to worry about.  But since its your vCenter server, good to have a backup of your database at least.

There's a good read on snapshot best practices, please have a look VMware KB:     Best practices for virtual machine snapshots in the VMware environment

I will doing this operation while I will be connected to it through vSphere client. I will face any disconnection ? OR the hosts in cluster will face any interruption with this ?

No. As long as you are "deleting" the snapshot there wont be any change of state for the VM. Hence, ideally you should not face any disconnection.
But if you revert back to any previous snapshot, state of VM after the revert operation depends on the type of snapshot that you have taken.

~dGeorgey

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