In Windows 2012, a provider "Microsoft CSV Shadow Copy provider" is introduced and the backup requestor must use this provider for a CSV volume in order to take application VSS snapshot to a Hyper-V VM.

My question is, in an environment where a hardware provider is available, how can we take application hardware snapshot? My confusion is, in order to take hardware snapshot, we need to use hardware provider for the CSV volume, however, in order to take application consistent snapshot, we need to use Microsoft CSV Shadow Copy provider. How can I use both for one same CSV volume?

Thanks

Hi Sir,

Based on my understanding , hardware snapshot is non-application consistent snapshot as you mentioned  .

You can contact hardware vendor to disable hardware VSS provider then just use software vss.

"By Default, DPM 2010 will attempt to use a VSS Hardware provider to take snapshots of hyper-V guests located on a SAN. There may be circumstances when you might want DPM to use the in-box VSS Software provider instead of the installed VSS Hardware provider for your SAN when doing Hyper-V backups. This may be because hardware licensing has not yet been activated, or perhaps problems with the SAN (space considerations) etc. and prevents hyper-V backups from getting done.


To overcome that add the following Key on the Hyper-V host(s) you don't want DPM to use the hadware vss provider.

[Software\Microsoft\Microsoft Data Protection Manager\Agent\UseSystemSoftwareProvider]"

I quoted it from a reply within following article :

https://technet.microsoft.com/en-us/library/ff634192.aspx

Best Regards,

Elton Ji

Elton,

Thank you for your reply. From your statement "Based on my understanding , hardware snapshot is non-application consistent snapshot as you mentioned  ." Do you mean we can not take consistent hardware snapshot on Windows 2012 and later? I didn't see any document this. Can you share me where you get it? Consistency is so important to customers, thereby, it is somehow a rash decision to disable consistent snapshot for hardware providers.

Thanks.

In Windows 2012, a provider "Microsoft CSV Shadow Copy provider" is introduced and the backup requestor must use this provider for a CSV volume in order to take application VSS snapshot to a Hyper-V VM.

My question is, in an environment where a hardware provider is available, how can we take application hardware snapshot? My confusion is, in order to take hardware snapshot, we need to use hardware provider for the CSV volume, however, in order to take application consistent snapshot, we need to use Microsoft CSV Shadow Copy provider. How can I use both for one same CSV volume?

Thanks

You don't need to use both. MSFT default VSS is used with a dumb storage that cannot manage snapshorts on it's level so it (VSS) asks file system to flush and hold writes, signals VSS-aware application thru registered callbacks to complete I/O in a known state (transactions) and then writes Copy-on-Write snapshot with performance impact as all CoW thing. If hardware VSS is present then everything goes the same except taking file system snapshot in software DOES NOT HAPPEN, that's "offloaded" to smart storage vendor who does this job and represents snapshot as new LUN on the same device. Apps don't care what's below them: MSFT software implementation or vendor-specific hardware one. That's all :)