> Hello,
>
> I am moving my virtualisation from WS2003 / VS2005 / Dell 2950 to WS2008R2
> /
> HyperV / Dell T710 and looking to see what new features I should take
> advantage of.
>
> Servers have local disk for OS (RAID-1 + Swap), and FC SAN for guests. I
> am
> not interested in clustering as the redundancy in the T710s coupled with
> the
> use of MS-DPM for backup is enough for my SLAs.
>
> I’m mainly interested in whether to use disk pass through. Currently I
> have
> presented a reasonable sized disk to the host (eg 100-300GB) and then have
> a
> number of VHDs on this one disk. I have used expanding disks where I might
> setup the disk with a size of 40GB, but it only has a VHD of half that
> (i.e.
> reasonably efficient). I monitor the free space on the guest and host and
> can
> increase the size of the host disk on the fly using the SAN and DiskPart.
> If
> a guest needed more space I would shut the guest, create a new larger VHD,
> and use something like ShadowProtect to copy from the existing VHD to the
> new
> VHD.
>
> In HyperV I have the option of pass through. Today I experimented with
> presenting a 20GB disk to the host and then created a guest and told it to
> use the physical disk. I built this as 2008-x86 and all good. I then
> increased the size of the disk to 25GB, but now in disk management I have
> a
> 25GB disk that shows as a 20 + 5. I tried extending with DiskPart, but I
> wasn’t able.
>
> So if I decided to have a separate pass through disk for each guest, how
> can
> I allocate more space to them?
>
> I gather there are performance benefits, but there seems to be too many
> negatives to make this worthwhile? Does it sound wise to go down this
> path?
>
> Thanks
> Mick

> Hello,
>
> I am moving my virtualisation from WS2003 / VS2005 / Dell 2950 to WS2008R2 /
> HyperV / Dell T710 and looking to see what new features I should take
> advantage of.
>
> Servers have local disk for OS (RAID-1 + Swap), and FC SAN for guests. I am
> not interested in clustering as the redundancy in the T710s coupled with the
> use of MS-DPM for backup is enough for my SLAs.
>
> I’m mainly interested in whether to use disk pass through. Currently I have
> presented a reasonable sized disk to the host (eg 100-300GB) and then have a
> number of VHDs on this one disk. I have used expanding disks where I might
> setup the disk with a size of 40GB, but it only has a VHD of half that (i.e.
> reasonably efficient). I monitor the free space on the guest and host and can
> increase the size of the host disk on the fly using the SAN and DiskPart. If
> a guest needed more space I would shut the guest, create a new larger VHD,
> and use something like ShadowProtect to copy from the existing VHD to the new
> VHD.
>
> In HyperV I have the option of pass through. Today I experimented with
> presenting a 20GB disk to the host and then created a guest and told it to
> use the physical disk. I built this as 2008-x86 and all good. I then
> increased the size of the disk to 25GB, but now in disk management I have a
> 25GB disk that shows as a 20 + 5. I tried extending with DiskPart, but I
> wasn’t able.
>
> So if I decided to have a separate pass through disk for each guest, how can
> I allocate more space to them?
>
> I gather there are performance benefits, but there seems to be too many
> negatives to make this worthwhile? Does it sound wise to go down this path?
>
> Thanks
> Mick