Hi All, I have done a quick google search and cant find anything on it, would anyone be able to advise if / how with AHV to check / change a VMs disk configuration so that a disk isnt included in a snapshot? the same way vmware has dependent and independent disks.
Thanks
Stewart
Best answer by ktelep
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+5
I’m curious as to what your use case is for this? I ask because there are certain workflows in VMWare that tend to require excluding a specific disk from snapshots for performance reasons and those are usually the driving factors in using independent disks. Since these issues don’t existing in AHV, often it doesn’t make sense to exclude a particular volume.
Are you looking to do this as a one-off event or as part of a schedule?
High level, you could do this by creating a Volume Group with just that vdisk in it, then attach the VG to the Virtual Machine. When you take a VM level snapshot it won’t snap the VG attached disk, just the ones defined as part of the VM.
There is always peril though in NOT including things in data protection schemes such as snapshots, so I’m curious as to the use case to make sure you don’t shoot yourself in the foot later when you try to do a recovery.
Hi ktelep, my use case for this is for SQL servers. In the past with SQL servers in VMware we would set the OS disk as snapable, but the data and log drives to not be included in snaps. This was for two reasons, firstly when doing OS patching we dont want to snap the whole VM as the snap grows huge due to SQL data changes, so we only snap the OS, and the data drives keep going, this way if we have to roll back an OS patch we dont have to roll back the database and lose transactions.
Secondly, when doing backups of the VM, we use the VM level backup for the OS, so base VM, but use SQL agent based back ups for the Data and Logs, so dont need to be included in the full VM level backup.
So its a once off event, setup at server creation usually.
would the Volume group work for this purpose?
+5
Absolutely. Simply place all the volumes that are a part of SQL in a Volume Group, and attach that to the VM. When a snapshot is run against the VM it will NOT snap the volume group, just the OS disk.
I *highly* recommend reading our SQL Best Practices Guide, specifically the portion about Storage located here: https://portal.nutanix.com/page/documents/solutions/details?targetId=BP-2015-Microsoft-SQL-Server:BP-2015-Microsoft-SQL-Server
great thanks for confirming. and the link.
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