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Scottdotnot - 14 Jul 2006 20:53 GMT

We have the luxury, or burden, of selecting our new storage system for our
future Exchange 2007 servers. We currently have 2 168 disk HP EVA 5000
systems for out Exchange 2003 boxes. We are looking at the EVA 8000, EMC
CX3-40 and 3PAR S400. Does anyone have any good links that compare the
prices vs performance of these systems?

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Al Mulnick - 15 Jul 2006 18:28 GMT

I don't have any links that compare them, but I notice you don't have NetApp
on that list? Any particular reason for that?
You currently have a high-performance system making me think you want some
high-performance and Exchange-dedicated systems. Exchange 2007 is currently
slated to relieve some of the IOPS cost via higher memory. It's all
speculation right now though, as the final numbers aren't in. Until they
are, it's going to be a tough call to figure out if you'll be better off
with the past rule of thumb of "throw iops at it" vs. using more memory and
requiring less spindles to achieve similar performance. It's a lot to ask
Microsoft to undo 10 years of thinking/philosophy and code in one release
but there's no telling how long they've been at it. You're early and I
suspect you don't have much choice in the timing of your budget.

You may want to call and speak with the testing engineers and see where the
current reality is. Not sure they'll do that, but it's worth a shot.

Al

> We have the luxury, or burden, of selecting our new storage system for our
> future Exchange 2007 servers. We currently have 2 168 disk HP EVA 5000
> systems for out Exchange 2003 boxes. We are looking at the EVA 8000, EMC
> CX3-40 and 3PAR S400. Does anyone have any good links that compare the
> prices vs performance of these systems?

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John Fullbright [MVP] - 16 Jul 2006 20:09 GMT

It's really all about about the write penalty, and with performance
improvements in E2007 will continue to be.

A decade ago, you had Exchange 5.X and an 8:1 read/write ratio. The impact
of write penalty was low beacuse writes only represented 12% or so of all
write operations. Today we have Eexchange 2003 and client side caching in
OL2K3, and the read/write ratio is more like 2:1. At this level, the impact
of write penalty is enough that RAID is no longer a viable option (Even the
Dell storage planner will show you at 2X the spindles you would use with
RAID 10). In Exchange 2007, the read/write ratio will (presumably) drop
further making write performance all the more important.

Is is unfortunate that you do not consider Netapp in the mix. While HP can
offer you RAID 5 (with a write penalty of 4) and RAID 10 (with a write
penalty of 2), and EMC can offer you essentially the same choices, NetApp
has no write penalty. This is due to a much more robust virtualization
layer that HP and EMC just don't have. The virualization layer implements a
'never overwrite" policy and coalesces all writes to new space. An artifact
of that is taking a snapshot does not involve copiny data; its already ther.
A snapshot on this platform is very low overhead and involves copying the
inode map, and not taking the action of freeing the old block. With 250
snapshots in place for a volume there is neglible performance degredation.
That's something else EMC and HP can't do.

http://www.netapp.com/ftp/veritest-netapp-comp-analysis2005.pdf
http://www.netapp.com/library/tr/3321.pdf

>I don't have any links that compare them, but I notice you don't have
>NetApp on that list? Any particular reason for that?
[quoted text clipped - 21 lines]
>> CX3-40 and 3PAR S400. Does anyone have any good links that compare the
>> prices vs performance of these systems?

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Scottdotnot - 17 Jul 2006 15:48 GMT

Thanks, we were primarily looking at systems we already have some experience
with onsite. I’ll add NetApp to the list. However, just a note on our HP
EVA systems they are all set up for Raid 10, and have been extremely
reliable. I think the heavy IOP requirement will be reduced in E2007, from
everything I have seen and read, but we still want a fast solution. With
Bigger mailboxes and more applications tying into the store we just don’t
want to have any questions about storage performance.

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> It's really all about about the write penalty, and with performance
> improvements in E2007 will continue to be.
[quoted text clipped - 48 lines]
> >> CX3-40 and 3PAR S400. Does anyone have any good links that compare the
> >> prices vs performance of these systems?

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John Fullbright [MVP] - 18 Jul 2006 01:58 GMT

RAID 10 has a write penalty of 2, and HP has done a good job documenting
exchange configurations. On the EVA, you can create quite large disk
groups, or pools of spindles, and then carve virtual RAID volumes out of the
space. I lpersonally like this approach better than the EMC (clariion)
aproach of RAID groups of a specific RAID type. NetApp is worth a look, and
it's good to hear that you will add them to the list. The virtualization
layer is much more sophisticated, and the result is no write penalty (a
write penalty of 1). Take a look at backups as well, Netapp has some great
advantages in the area of snapshots if you go that route.

John

> Thanks, we were primarily looking at systems we already have some
> experience
[quoted text clipped - 76 lines]
>> >> the
>> >> prices vs performance of these systems?

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