Being new to a VM type environment, I'm trying to spec out a machine
to run Win2K8 and several app VMs and a virtual MS SQL 2008 machine.

When planning for SQL performance, generally you want at least 7
disks. RAID 1 for the OS, RAID 1 for the SQL transaction logs and
RAID 5 for the SQL database. With that kind of design consideration,
how does this work in a VM? My only VM experience is with Virtual
Server (pre Microsoft) and back then there was just one flat file that
was created on a disk.

Thanks!

You can allocate physical discs as virtuals, so you could basically do the
same thing you were doing if your Machine has enough drives in it.

another approach would be to create Virtual hard drives and spread them
around several physicals.

2008 is great, however I found very limited raid support - adaptec, 3ware,
and arcea all do not have 2008 drivers for thier raid cards at this point.

the ICH9R raid controller that comes with many intel based desktop boards
seems to work on 2008, but in my case, the raid 5 performance was severely
limited in 2008 (50mb/sec read, 15 mb/sec write)
I ended up scrapping plans for raid 5 for now, and have gone with 2 separate
mirror sets (4 drives) this gives me some flexibility to put things in
different places.

I haven't worked with storage area networks, but It seems 2008 Hyper-v
server supports iscsi, so that might be an option on the higer end (cost wise)



"robro" wrote:

> Being new to a VM type environment, I'm trying to spec out a machine
> to run Win2K8 and several app VMs and a virtual MS SQL 2008 machine.
>
> When planning for SQL performance, generally you want at least 7
> disks. RAID 1 for the OS, RAID 1 for the SQL transaction logs and
> RAID 5 for the SQL database. With that kind of design consideration,
> how does this work in a VM? My only VM experience is with Virtual
> Server (pre Microsoft) and back then there was just one flat file that
> was created on a disk.
>
> Thanks!
>