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Virtfile.sys Version?

Level 2

I have a request from Microsoft to "upgrade" to the latest version of the vertfile.sys.  My current version is 2.2.115 and from what I can tell this is the latest version for Netbackup 7.7.3 where the client is installed on my Hyper-V Windows 2012 R2 server.  Is this the case and MS is just blowing steam?


Chris Townsend


Level 6
Partner    VIP    Accredited Certified

What are their concerns with the current version of virtfile.sys?

The only TNs I could find was this one w.r.t. NBU 8.0 installation (fixed in 8.1):

And this one w.r.t. Backup Exec AD GRT backup (fixed in BE2014)

NBU 8.1.2 is the latest version if you want to upgrade your entire environment. 

Level 6

Yes, Microsoft is just blowing smoke. They were when they panicked a customer to make us change Virtfile.sys. If you have access to a newer version, you can drop it into your 7.7.3 environment with no harm. You have to install it. I think you can do that by right-clicking the file. You have to put the matching virtAPI.dll in your NetBackup\bin folder, or NetBackup won't load BEDS.

Would this new version of vertifile.sys then need to be installed on the NetBackup server as well as the client or is it just a client component.  My problem is that all of our servers have the same version that we currently have.  In my opinion, it does make sense to "upgrade" our entire environment because one MS server is behaving badly.



Virtfile.sys is the VFF driver, registered with the Windows file system as a "minifilter." The fake issue was the level ("altitude") at which it's loaded. Way back, Microsoft issued an altitude number to Symantec, but Symantec had two drivers to load, so they loaded the VFF driver at a higher (safer) altitude. That's where Microsoft was blowing smoke. A minifilter loaded later is farther from the file system and has less opportunity to do harm. (This was not the Microsoft home office. It was a local support tech.)

The other NetBackup filter has long since been abandoned, so the change is to load virtfile.sys in its designated slot.

We did not issue an EEB for 7.7.3 because the "problem" did not merit one.

It only needs to be on the Windows clients. You will notice that it goes in a Windows system directory. Find where the one you have is. The altitude change takes effect at system boot.