Question: Is Veeam "Shadow Copy" aware?

[Kaelteth]

Hi everyone,

I'm in the process of deploying Veeam, and my one big question at this point...is Veeam aware of shadow copies on a volume, to the point that it will NOT back up the shadow copies generated?

I have a major filestore where I love using shadow copies to help my users, but I don't want my backup size to grow by the space used on disk for the copies.

Anyone know? Thanks!

[tsightler]

Veeam's job is to backup your VM exactly as it exist, so it will also backup the "shadow copies". If you restored your entire VM, wouldn't you want your shadow copies to still be available? If not, you can configure your shadow copy storage volume to use space on a separate volume (for example, create an "S:" drive, and use it for shadow copy storage for the "D:" drive), and then exclude the shadow storage volume from the Veeam backup using disk exclusions.

[Kaelteth]

I guess I'm seeing the Shadow Copy itself as more of a nicety to the end user than anything else, and I guess saving me some time from having to "go to the tape", now Veeam, to restore an individual file if necessary.

Backing up the shadow copy in addition to backing up the VM's on a continious basis just seems like making a backup of a backup....it "wastes" space - especially since I want to backup to a remote location over WAN.

I'll go your route though for separating the shadow copy from the rest of the VM.

[rawtaz]

Isn't it true that as Veeam uses CBT to copy all blocks that have changed (except swap if that is excluded), both previous and current "versions" (blocks, technically) of files will be backed, regardless of whether you have shadow copies turned on or off (assuming you dont move the shadow copies to a separate and not backed up disk)? So basically the same amount of data will be backed up regardless of shadow copies?

If that is true, what is the real actual difference for the backup if you turn on shadow copies in the VM vs having them off? What downsides are there to turning on shadow copies in the Windows VM?

[Vitaliy S.]

Yes, Veeam retrieves all blocks that were reported as changed by VMware CBT driver.

both previous and current "versions" (blocks, technically) of files will be backed, regardless of whether you have shadow copies turned on or off (assuming you dont move the shadow copies to a separate and not backed up disk)?

Not sure I follow you here, but If volume shadow copy is disabled, then there will be no previous "versions" of the blocks, and data will backed up only once.

[uros678]

Hello,

just a quick question. What happens if you enable shadow copies on a deduplicated volume (2012 R2) that is used for file sharing? CBT is enabled in veeam. Will that have any inpact on the amount of data that will be "rescaned" and transfered to the backup?

Thanks for the answers.

Kind regards,

Uros

[foggy]

Hello Uroš, please review considerations above. Basically, yes, there will be an impact of enabling shadow copies, since they change disk blocks inside a VM.

[rntguy]

A client has a volume where volume snapshots are pointed to for space. Does Veeam ignore these when it backs up a VM? Or do we need to manually exclude that volume in the job?

[foggy]

Could you please clarify what volume snapshots are you talking about?

[rntguy]

The E drive uses the V drive for Shadow Copies.
https://ibb.co/eLOnoF

[foggy]

Ok, got it, thanks. You need to explicitly exclude this volume from the processing.

[rntguy]

thanks.

[rntguy]

one concern about this method is if the customer adds another volume without telling us now it won't be backed up.

[foggy]

They can use one of the unsupported disk types (independent, iSCSI...) that will be skipped automatically without the need to enable exclusions.