Host-based backup of Microsoft Hyper-V VMs.
Post Reply
rlspeeks
Enthusiast
Posts: 45
Liked: 5 times
Joined: Feb 19, 2019 4:42 pm
Full Name: Rebecca Speeks
Contact:

Exclude SQL database drives

Post by rlspeeks »

It appears I have this backup job created correctly. The SQL admins want to backup their databases themselves. I've excluded all drives that have databases on them. (I'm not sure how to insert a screenshot- sorry) On the Job History, it shows "Excluding disk xxxxx" for each disk I've excluded.
However, they still report Spotlight I/O errors - SQL log is the same type of message (freezing I/O due to VSS method, etc.).
They show the databases still getting backed up? I'm not sure what I'm doing wrong?
Mildur
Product Manager
Posts: 8481
Liked: 2203 times
Joined: May 13, 2017 4:51 pm
Full Name: Fabian K.
Location: Switzerland
Contact:

Re: Exclude SQL database drives

Post by Mildur »

You need to configure your application aware processing for only „Copy“ the sql databases and not truncating it‘s log files.

Perform Copy only should the option you are looking for:

https://helpcenter.veeam.com/docs/backu ... ml?ver=110
Select Perform copy only if you use another backup tool to perform VM guest level backup, and this tool maintains consistency of the database state. Veeam Backup & Replication will create a copy-only backup for the selected VM. The copy only backup preserves the chain of full/differential backup files and transaction logs on the VM. For more information, see Microsoft Docs.
But i had some customer, where this option wasn‘t enough. We had to disable the application aware processing completely. Second Option we had to turn off the option „Enable VMware tools quiescence“.
Vmware tools quiescence are messing around with the vss writer for the sql database too.
Now we have only crash consistent backup, but the customer is aware of that. He is responsible now for the sql backups and not we as the MSP.

https://helpcenter.veeam.com/docs/backu ... ml?ver=110
Product Management Analyst @ Veeam Software
soncscy
Veteran
Posts: 643
Liked: 312 times
Joined: Aug 04, 2019 2:57 pm
Full Name: Harvey
Contact:

Re: Exclude SQL database drives

Post by soncscy »

Do they want to exclude the databases from VSS processing also? Disk exclusions only stop the data from being backed up during the backup as I learned some time ago, the disks are still included in the relevant checkpoints/diskshadow.

I believe there's a registry value EnableDBExclusions which will let you exclude the DBs from processing. It adds a UI option in the main Veeam menu (which is hidden for a reason I don't quite understand :D) But I believe this is what your DBAs want if you're going to use application aware for this backup. Or just turn off Application Aware. (but then...what's the point of the backup?)

Also I'm going a little crazy right now as I swear I remember reading a topic about HyperV and SQL processing specifically, but I cannot find it except for a small mention in my Evernote. Maybe it was just for older versions of Veeam...
rlspeeks
Enthusiast
Posts: 45
Liked: 5 times
Joined: Feb 19, 2019 4:42 pm
Full Name: Rebecca Speeks
Contact:

Re: Exclude SQL database drives

Post by rlspeeks »

@Mildur - Copy only is selected. Sorry I can't insert a screenshot. Not only is "Copy Only" selected, I have the drives where the database(s) reside excluded from backup all together. I have verified this by attempting a restore and those drives are not there at all.
However, the SQL DBA's are still showing the database(s) as either getting backed up or I/O latency during the backup window. It is consistent to when backups are being performed.
I guess @soncscy answered that question as they are still included in relevant checkpoints/diskshadow? This is Hyper-V (btw).
It sounds like my only option is to either turn off Application Aware processing or use this registry value?
I just don't understand, if given the option to exclude an entire drive from backup, why touch it at all?
soncscy
Veteran
Posts: 643
Liked: 312 times
Joined: Aug 04, 2019 2:57 pm
Full Name: Harvey
Contact:

Re: Exclude SQL database drives

Post by soncscy » 1 person likes this post

When you do the in-guest disk shadow, regardless of the hypervisor, all volumes are added for processing when Veeam does. This makes sense to me because otherwise you end up with potentially crash-consistent data in the backup file and that means data corruption.

I think what your DBAs are asking for is to avoid VSS processing, which as we know has implications for the transaction log backups (multiple applications handling log backups will break each other's backups, as the current LSN chain will be broken and cannot be applied to the Full DB backup each application has).

So the disk exclusions aren't really relevant here -- that just stops them from being backed up (i.e., the disk data physically copied and processed into a backup file. Disk exclusions are about data management at the Hypervisor level, not about in-guest anything).

Try either disabling AAIP entirely or use the registry value and try excluding the databases -- see if it helps. Else, as you probably know backups have a non-0 I/O penalty even on HyperV, so this might just not be avoidable.
Post Reply

Who is online

Users browsing this forum: No registered users and 7 guests