Re: Exchange 2007 - Multiple SG per LUN?

On 3 Dec, 18:20, AJ <andyjone...@xxxxxxxxxxxxx> wrote:
On 3 Dec, 17:34, "Mark Arnold [MVP]" <m...@xxxxxxxx> wrote:





On Mon, 3 Dec 2007 09:07:48 -0800 (PST), AJ

<andyjone...@xxxxxxxxxxxxx> wrote:
I see MS have put multiple storage groups on one LUN as opposed to
spliting out one LUN per SG, which is what I tended to do with
Exchange 2003.

Can someone give me an explanation of why this is currently the
preffered way to do things? what benefit would this provide over
separating out. I would think having seperate RAID10 arrays would be
better in regards to performance or is that not the case? I can see
there would be issues with drive letters and needing volume mount
points etc which would complicate things but what about for smaller
servers that could get away with just using drive letters. Also I
could see having multiple LUNS beneficial from a backup perspective.

Comments greatly appreciated.

Thanks

AJ

Raid10 would be damn awful, nay, appalling, performance wise.
Putting the information onto different arrays should be obvious but
anyway, are two fold. 1- fragging of the stores (minor but relevant)
and 2- i/o performance.

Personally I wouldn't put multiple SGs onto one LUN. If the throughput
wasn't going to be bad I'd put a couple of SG logs onto a LUN to
optimise space utilisation.

Really you're not asking the question you think you are. A LUN has got
practically nothing to do with disk or space utilisation. The LUN is
exactly that, a logical presentation of something physical. The LUN
could reference just about anything.

Talk to us about the back end storage, who makes it, is it DAS or SAN,
what RAID you can have, how many disks are in the subsystem and their
speed/capacity etc.- Hide quoted text -

- Show quoted text -

Sorry I meant RAID 1+0!!!! and yes I know what a LUN is :)

It's DAS/HP MSA array. I was just wondering why best practice appears
to of changed. I would of normally seperated each SG onto its own RAID
1+0 LUN for max performance and also have the transaction logs (RAID1)
on their own LUNs seeing as we will have a small number of storage
groups. I can understand why combining them would be beneficial on a
much larger server housing a large number of storage groups. We were
planning on 4 storage groups each with 1 store (following BP and
because its a CCR server). With a 4 drive minimum for RAID 1+0 that
would be 16 drives (for the stores) and this configuration would
provide enough IOPS and capacity to support the user base. For the
transaction logs we were planning on 4 RAID1 LUNS making a total of 24
disks.

Now why would combining some of these stores on one LUN be beneficial
especially seeing as the disks have already been bought!?

From your reply, I think you are agreeing with my view point?

Thanks

AJ- Hide quoted text -

- Show quoted text -

Hmm thinking some more maybe it's because the reduction in I/O
requirements for Exchange 2007 and the balance of cost versus
performance.
.

Relevant Pages

  • Re: Exchange 2007 - Multiple SG per LUN?
    ... I would of normally seperated each SG onto its own RAID ... 1+0 LUN for max performance and also have the transaction logs ... Now why would combining some of these stores on one LUN be beneficial ... especially seeing as the disks have already been bought!? ...
    (microsoft.public.exchange.admin)
  • Re: Exchange 2007 - Multiple SG per LUN?
    ... 1+0 LUN for max performance and also have the transaction logs (RAID1) ... Now why would combining some of these stores on one LUN be beneficial ... especially seeing as the disks have already been bought!? ...
    (microsoft.public.exchange.admin)
  • Re: SAN drive config for SQL Cluster
    ... other containing RAID 0+1 LUNs. ... Then plan the LUN ... >> SAN on different LUN's, ... >> different parts of the same SAN disks. ...
    (microsoft.public.sqlserver.clustering)
  • Re: Solaris 9 vxfs equivalent ?
    ... Raid 5 isn't has bad has it was, It still is a solution cost effective ... you'll have to make a decision how the Disks ... One idea is to have a single LUN and place your FS on top of that LUN. ... stripe, you have to see if the best is to use a stripe unit of 16K (and ...
    (comp.unix.solaris)
  • Re: Storage group performance
    ... that matters unless you're going to separate storage groups onto separate ... come up with a layout for my storage groups/data stores to maximize ... Total users: 900 ... Put each Transaction Logs on different LUN ...
    (microsoft.public.exchange.setup)
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