RAID 5 versus RAID 1+0 - Microsoft Exchange

You are the second person to post about this in a fairly short period of
time.
Is there a common demoninator in these 2 cases? Same SP & hot fix level.
Same hardware? Same AV product?

Try and contact dgeedgee to see if he got a solution

/Simon
"KBing" <KBing@discussions.microsoft.com> wrote in message
news:5EC3FA0A-7FE8-474E-B8F3-D788679653FD@microsoft.com...
> I'm running Exchange 2003 Enterprise, Active Passive cluster on a SAN.
>
> We have the .STM files on a separate disk set configured as RAID 5
> currently. We are experiencing periodic slowdown with the .STM files to
> the
> point where we get plenty of RPC dialog boxes on Outlook clients.
>
> Perfwiz and the SAN ****yzer both show high disk I/O latency on the disk
> set
> that the .STM files are on. All other drives are well within the Microsoft
> recommended limits <20ms.
>
> Has anyone switched from RAID 5 to RAID 1+0? If so, what was your
> performance experience? Good / bad?

On Tue, 24 Oct 2006 10:47:02 -0700, KBing
<KBing@discussions.microsoft.com> wrote:

>I'm running Exchange 2003 Enterprise, Active Passive cluster on a SAN.
>
>We have the .STM files on a separate disk set configured as RAID 5
>currently. We are experiencing periodic slowdown with the .STM files to the
>point where we get plenty of RPC dialog boxes on Outlook clients.
>
>Perfwiz and the SAN ****yzer both show high disk I/O latency on the disk set
>that the .STM files are on. All other drives are well within the Microsoft
>recommended limits <20ms.
>
>Has anyone switched from RAID 5 to RAID 1+0? If so, what was your
>performance experience? Good / bad?

Databases are, depending on your SAN, on RAID1 or better, 1+0. Think
of random reads. RAID1 is better at random reads like that.
That said, it's often down to the SAN vendor. An enormous amount of
people use NetApp on which you get RAID-DP, an implementation of
RAID6. That has some challenges and requires someone clever to work
all the volumes out. EMC is much more conventional and although the
disks can be all over the show the RAIDing is the same as on-box RAID
requirements.