VSS on CDP volume with Starwind iSCSI free version

boka · Thu Sep 29, 2011 12:00 pm

Take a look at attached screenshot.
What am I doing wrong when trying to switch on shadow copies right in the remote iSCSI disk?
I'm using free version, volume was created as CDP.

Fri Sep 30, 2011 10:00 am

And what the problem really is? I mean what's not working for you? Sorry but it's not clear from attached screenshot. Please clarify. Thanks!

boka · Mon Oct 03, 2011 8:53 am

Can I use the iSCSI target disk itself for storing Shadow Copies?
The topmost window "Parameters" on screenshot shows no S: drive in a choice of possible storage of shadows. And below it it's visible that S: is a letter assigned to iSCSI drive.

[ non-English text removed ]

Mon Oct 03, 2011 9:55 am

You should be able to do unless there are some VSS aware restrictitions on placing VSS snapshots on SAN volumes.

boka · Mon Oct 03, 2011 10:21 am

Do you know any of them?
I cannof find.
And as you see I can fluently do it on any other "DAS" volumes.
Do I need the Starwind VSS service to be installed on initiator side?

Mon Oct 03, 2011 10:30 am

No, StarWind VSS agent is intended to serve totally different purpose.

boka · Mon Oct 03, 2011 10:52 am

..and the main part of my question - why?
Still opened?

Tue Oct 04, 2011 9:33 pm

Microsoft has some restrictions on using VSS on iSCSIPrt controlled volumes. Tomorrow Tolya will try to reproduce your issue. What OS (exact version please) are you using?

Constantin (staff) · Wed Oct 05, 2011 10:53 am

The main goal of VSS Provider is to guarantee consistency of data on snapshot.
It works following way: you click create snapshot button in StarWind GUI. StarWind service handles this command and requests for creating new delta file. Meanwhile VSS provider installed on client machine checks waits for creating snapshot. When service gets this command he informs the OS and all apps (if they are VSS aware) that all cached and not yet written to disk data must be flushed to create snapshot.
So, when you try to configure VSS in disk options - you are trying to configure Windows VSS, not StarWind`s. Our VSS provider cannot be configured through Windows at all. Also if you want to store you snapshots on another disk you should configure this ability in StarWind GUI during creation the snapshot target.

Constantin (staff) · Wed Oct 05, 2011 2:25 pm

To implement required scheme you need to use command line tool called VSSadmin. It should be run with administrative privileges. Basically this CLI tool is doing the same what you are doing in GUI, but according to MS forums this is recommended way to configure VSS.
Here you can find options how to run it: http://technet.microsoft.com/en-us/libr ... 10%29.aspx