In our quarterly study on Exchange Solution Reviewed Program (ESRP) results we show a number of charts to get a good picture of storage subsystem performance under Exchange workloads. The two that are of interest to most data centers are both the normalized and un-normalized database transfer (DB xfer) charts. The problem with un-normalized DB xfer charts is that the subsystem supporting the largest mailbox count normally shows up best, and the rest of the results are highly correlated to mailbox count. In contrast, the normalized view of DB xfers tends to discount high mailbox counts and shows a more even handed view of performance.
We show above a normalized view of ESRP results for the category that were available last month. A couple of caveats are warranted here:
- Normalized results don’t necessarily scale – results shown in the chart range from 5,400 mailboxes (#1) to 100,000 mailboxes (#6). While normalization should allow one to see what a storage subsystem could do for any mailbox count. It is highly unlikely that one would configure the HDS AMS2100 to support 100,000 mailboxes and it is equally unlikely that one would configure the HDS USP-V to support 5,400 mailboxes.
- The higher count mailbox results tend to cluster when normalized – With over 20,000 mailboxes, one can no longer just use one big Exchange server and given the multiple servers driving the single storage subsystem, results tend to shrink when normalized. So one should probably compare like mailbox counts rather than just depend on normalization to iron out the mailbox count differences.
There are a number of storage vendors in this Top 10. There are no standouts here, the midrange systems from HDS, HP, and IBM seem to hold down the top 5 and the high end subsystems from EMC, HDS, and 3PAR seem to own the bottom 5 slots.
However, Pillar is fairly unusual in that their 8.5Kmbx result came in at #4 and their 12.8Kmbx result came in at #8. In contrast, the un-normalized results for this chart appear exactly the same. Which brings up yet another caveat, when running two benchmarks with the same system, normalization may show a difference where none exists.
The full report on the latest ESRP results will be up on our website later this month but if you want to get this information earlier and receive your own copy of our newsletter – just subscribe by emailing us.