Migrating Hyper-V VM with pass thru disk - should this work?

[sidewinder]

I'm re-organising our Hyper-V hosts, and most migration is easy with SCVMM but this one could be a problem.

 

It's a file server with a fixed size VHD for the system disk, but a local RAID5 array of 3 disks for the data connected as a pass thru disk (as it seemed like there would be too much overhead making it a virtual disk)

 

If I moved the VM to another host, recreated another pass-thru disk on there (probably a larger size one), then restored all the data to that disk, should all the shares stay intact? I'm thinking in theory they should, since everything about them is stored on the system disk, and as long as the data is in the right place (D:/) with the correct permissions, it shouldnt matter that it is technically a different disk.

 

Is that correct? I'm going to test all this before I start anyway, but just wondering whether I'm correct or am I missing anything?

[SYNACK]

Yes, and if using 2k8r2 use fixed VHD, it is only about 5% slower than passthrough and more portable.

[SYNACK]

Strike that, less than a few percent performance loss on some areas and gains in others:

Hyper-V pass-through disk performance vs. fixed size VHD files and dynamic VHD files in Windows Server 2008 R2 « Clustering For Mere Mortals

 

Hyper-V pass-through disk performance vs. fixed size VHD files and dynamic VHD files in Windows Server 2008 R2 « Zeros & Ones

 

Summary, use fixed VHDs.

[sidewinder]

That is really interesting actually, thanks!

To be honest I didn't really do a huge amount of research when I set it up, just assumed there would be a huge overhead.

 

I'll make it all fixed size VHDs then, means I can split the data up a bit too