Backup VM's with no network connectivity

[mdornfeld]

Have an interesting situation coming up, we are relocating our SAN. In the process of doing so, I've been requested to do a full backup with all of the VM's powered down and network connectivity disabled from the ESXi hosts (they want to move the switch while I'm running backups).

To do this, I believe I have to leave the following servers powered up:
-Veeam backup server
-vCenter

Now the questions. All servers use "Direct SAN connection" for backup, so I don't think that not having network on the Veeam server (local SATA storage for backups), vCenter, or the ESX hosts will be an issue, right?
Also, the majority of my servers use VSS with a windows username and password and some, such as Exchange and SQL servers, will truncate the logs, and I have VSS set for "Require Successful Application Processing". What happens with them when Veeam tries to back them up while they are turned off? Does the job fail, or does the VSS action just not occur?

Any other problems you can think of for this scenario?

Thank you.

[tsightler]

This won't work. You have to have communication with the ESXi hosts to do a backup, no matter the mode. The ESXi host actually handles the process of taking a snapshot, and a snapshot is still taken even if the VM is powered off, since, well, you might decide to power the VM on during the backup.

As for your other question, VSS is not attempted if the VM is powered off.

[mdornfeld]

Doh! Makes sense though. Thanks Tom.

[mdornfeld]

>VSS is not attempted if the VM is powered off
So I presume it auto-passes the "Require Successful Application Processing" check and just backs up the VM in the powered off state?

[Gostev]

No, it will not pass the test for successful application processing. You do not want to restore a backup of domain controller that was turned off during the backup, but was then turned on and worked for some time before it failed.

[mdornfeld]

I understand that the AD servers are kind of an odd-bird with limited use for the backups. I think the only time I'd ever restore one of them is if I lost all of them... otherwise I'd think you'd be safer just rebuilding them from scratch and replicating them off of the whatever good AD server was still out there.

Anyway, to get my cleanest backup of a non-AD VM, would you recommend I leave it on or off during Veeam backup? I've never really had the option before to turn them off... so this is new territory. Part of me just wants to leave the VM's on, because why mess with something that works, but if you tell me the backup is more foolproof with it turned off or the backup will go faster, then I'll turn them off.

Thanks guys,
Matt

[Gostev]

I recommend to keep them on. Why create unneeded downtime? Can you even do this for your VMs? We at Veeam have quite small environment, with only a handful of production servers, but I cannot imagine turning them off during backup. Someone is always out there working! Almost 3am my time now, and I am doing email... 1 more hour, and APAC guys will wake up... etc.

[tsightler]

He's just referring to this one special case that he mentioned in the first post. I'd just disable VSS to backup these powered off VM's.

That being said, there might be some issues with vCenter if all domain controllers are powered off unless vCenter is configured to use only local Windows accounts.

[mdornfeld]

I did a test over the weekend. Apparantly even if you "Require Successful Application Processing" for the VM, it WILL still backup even if the VM is turned off. This is contrary to what you said above Anton, so just wanted to mention.

You just get a message that states: "Validating guest agent availability for the VM Unable to use guest agent: VM is powered off"

Tom, I'm thinking I'll just leave the AD servers on along with vCenter to avoid any issues.

Thanks guys!