Linked Clone Questions

[prutter]

I am hoping in the near future to deploy osme new VM's to one department and have a couple questions to get a better understanding. Does the original VM (the one the snapshot is created from) need to remain on at all times? How is an update pushed out to all the vm's in a pool if a major update is needed?? Are there any Memory concerns associated with linked clone pools??? Any help in getting a better understanding is appreciated. I'm looking to do this sooner than later. Thanks in advance.

[tbuckholz]

The original VM does not need to stay on. I'm assuming you're using linked clones, in which case it makes a copy of the template at the snapshot point you specified and the clones are based off of that copy (one copy per datastore). You can turn the original template on or off, it doesnt matter. In fact, from what I've seen so far, once you've deployed the copy, you can pretty much do anything you want to the template and the pool won't care.

Once the template has been deployed, the copy is static as of that point. If you want to update the VMs (say with patches), you update your base template and take a new snapshot. You can then select to recompose your VMs (either all at once or individually) and it will create a new base template off your new snapshot, and then rebuild the selected VMs off that new copy.

I'm not sure what you mean by memory concerns. Each linked clone VM will consume memory like a normal VM. If you have 30 XP VMs off a 1GB RAM template, you could consume up to 30GB of RAM + overhead, shared pages etc notwithstanding.

[prutter]

Another question about updating a pool if i may? When you say update the template are you referring to the Parent VM? When i take a new snapshot will i have to go and edit the pool to point to the new snapshot? i need to be able to do this on a regular basis and trying to make sure what i'm in for. Any help is appreciated. Thanks again!

[admin]

Another question about updating a pool if i may? When you say update the template are you referring to the Parent VM? When i take a new snapshot will i have to go and edit the pool to point to the new snapshot? i need to be able to do this on a regular basis and trying to make sure what i'm in for. Any help is appreciated. Thanks again!

He is referring to the parent VM. You can use the recompose feature. When you use the wizard it will ask you which snapshot you want to use for the recompose operation.

This guide gives full details on using the recompose feature:

[prutter]

Then I ran into a problem i think. It refers to a "Summary" tab and i don't see one if the 4.0 Admin Console.

[admin]

Then I ran into a problem i think. It refers to a "Summary" tab and i don't see one if the 4.0 Admin Console.

If you have a pool already created you should see it in the left pane. If you click that pool it loads the view for the pool you clicked. Then there should be a summary tab.

[prutter]

Got it. Thank you!

[prutter]

One more question if i may. Can you have more than one snapshot of a parent VM without any issues? The reason for the question is that i tried it and tried to update the parent and never could get into the VM's again.

[Linjo]

Yes, that should not be any problem

What is the error?

Best regards,

Linjo

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[admin]

The maximum depth for 3.x used to be 32 snapshots per VM. I looked through the 4.0 docs but didn't find the answer yet.

[prutter]

Not sure what the error was. Didn't look at a log file but it said that the vm was unavailable. i have to deploy 15 VM's in a persistent pool and 6 of them need to have a different snapshot since those will have additional software than the others. i just wat to make sure there are no issues with this.

[tbuckholz]

Keep in mind that each different 'image' you use in a pool creates a copy which occupies additional space. If you only have 15 desktops and 6 of them need to have different components on them, you might be better off just cloning the original VM with the common software. YMMV.