I’ve been helping a client who have email performance issues. Problem is simple enough – most users mailboxes are in the multiple GB range, and there isn’t enough hardware to cope.
It’s all tier-1 hardware – SANs with lots of fast disks in RAID10, mulitple CPU servers. Just nowhere near enough to chew through the TBs of mailboxes and give decent response times.
As part of this we’ve been talking to Microsoft about strategic direction. The environment now is Exchange 2003, so an upgrade to Exchange 2007 with its better performance and memory usage, plus a pretty straightforward upgrade, all seems to be a no-brainer.
I’ve taken a bit of interest in Exchange 2010 and have it runninging in a semi-production environment. I read the blurb about how they have improved I/O further. But it never really occured to me how much of a step-change this new version is.
Basically, disk I/O and resilience are off the table as a concern. Microsofts advise is to forget even RAID, simply use the inbuilt replication technology to have 2,3,4… copies of mailboxes. A single (cheap, sata) disk will service a few hundred mailboxes of the monster size I’m dealing with.
For the first time outlook talks to the CAS server instead of the mailbox direct, which has allowed an easier redirect when a mailbox store goes down.
It’s hard to see why you would ever deploy a SAN for exchange again. In fact, you could arguably jettison a lot of resiliency features of your mailbox servers (dual power supplies, fans).
For many organisations, one mailbox server will be enough, with mutliple servers simply added for resilience (plus our CAS and RG servers of course).
The side effect of the move off the SAN for exchange is that because we dedicated lots of spindles to get decent performance out of exchange, we use a lot of GBs. This space can be set free, reconfigured as RAID5 for filespace or suchlike.
If you’re about to buy extra SAN storage because of email capacity issues, don’t. Go get Exchange 2010.