|
|
Gail wrote:
>
> Indeed. The problem with multiple SQL instances in VMs is IO. You can
> allocate CPUs and memory to specific VMs, but there's still a single IO
> channel, and SQL database tend to be IO bound more often than CPU or
> memory.
With Xen you can allocate whole disks or RAID-arrays or whatever and
amount X of RAM to be used straightly by the VM. In my experience the
lag is mostly unnoticeable (yes, it probably will be more noticeable
with DB-server, which I'm not running on VMs (well, there are MySQL
installations on at least 2 VM's, but they're really small DBs), but
depending on DB-size etc the saved cost of another HW can possibly give
you even better HW for that one machine to have better IOs for the DB,
it's not purely black and white).
Then again, MS surely don't want to support Xen, while they're working
on HyperV - no wonder SQL Server ain't supported on such
competitor-software ;).
--
Eero "Aero" Ahonen
http://www.zbxt.net
aer### [at] removethiszbxtnetinvalid
Post a reply to this message
|
|