Backup of Linked Clones

[gaadmin]

Hi all,

Can anyone advise me what the options are in terms of backup of linked clones in vCD?

I'm assuming that VADP backup of the linked clone VM wouldn't be enough, because you'd still need the base disk, and know how the two relate to each other?

[charliejllewell]

This is an interesting question and not one that I can fully answer. I can however share my findings. We are currently looking at backup products that work with vCD. Both venders we have shortlisted say they support linked clones although I have had no details as to what level. So I have conducted some testing and found that CBT cannot be used if the base clone was not configured to use it. This is because the backup tool sees a snapshot (used by vCD to create the linked clone) and cannot enable CBT. My theory is, if you enable CBT on the template (which I have done successfully) and then deploy a new VM from the catalog with fast provisiong enabled, you should be able to use CBT with the backup solution. This is because the source disk is read only so changed blocks should only be written to the cloned delta.

In theory when the first backup is done the backup system will read the disk information for each linked clone and create a copy of the data for each VM. After that it should be able to use CBT to see which blocks have changed per linked clone (source disk is read only) and then just backup those changes.

I will complete my testing and let you know the outcome.

[mayonnaise]

Hello

could you please share any results of your testing of linked clones VMs from vcloud

thanks ahead

[Court01]

I will be out of the office May 30th thru June 6th, and will have limited access to email.

[charliejllewell]

Right I have completed testing of linked clones with vCD 1.5.0 with two backup solutions, Commvault and Veeam and can confirm that both work with linked clones WITHOUT having to do any configuration on the source disk as I thought might be required. This is great news and vastly simplfies our vApp image creation.

It appears that every new linked clone deployed completes a full backup - as you would expect. Once complete CBT is used for any incremenatl backups for that clone and is enabled automatically by the backup solution.

I have also tested a restore of files from the backed up clone both full and incremental with no issues.

Finally I tested powering off a linked clone mid backup, adding it to catalog, powering it back on, deploying a new linked clone from the newly created catalog entry and backing that up. The original backup completed successfully. The newly deployed clone, did a full backup and then the second backup I ran used CBT both completed successfully.

So my conclusion is that both these backup solutions appear to support CBT with linked clones. Hope this helps, Charlie

[gaadmin]

Thanks very much for the feedback, will do some testing tonight, looks like it might not be as complicated as I thought!