I try to keep up with as many people who are interesting and important work in the field of Microsoft’s enterprise application products such as Exchange, SQL Server, and SharePoint and now and then it surprises me when someone really “gets it” in terms of their audience.
Denny Cherry is one of those guys. He presents topics not for the storage geeks among us, but for SQL geeks who could benefit from understanding more about how a SAN is set up and configured. A couple of days ago, he wrote a post summarized a recent presentation he gave to a group of SQL pro’s – a dry run for his upcoming SQL Pass presentation. What caught my eye is that he was generous enough to share his presentation materials online, for all to share and digest – great stuff on storage and virtualization for the SQL DBA.
A very smart dude – and I’ve happy to say I’ve had the pleasure of meeting him at EMC World in the bloggers lounge. I think I also walked past him a few times on Bourbon Street at TechEd, but … I can’t be sure :)
Anyway…. as an EMC employee, I was very happy to see the references to EMC, but (there’s always a but isn’t there) I did want to correct two minor corrections I would make on the materials:
1. Slide 22 indicates Exchange belongs on FC disks. I would just mention that at EMC, we’ve seen a lot of people put Exchange 2010 on SATA. RAID-protected SATA nonetheless, but SATA combined with Virtual Provisioning (EMC’s term for Thin Provisioning) works very well for most situations. Caveats apply when using SATA and replicating that data, of course – but tread carefully, and it can be done. Thin Provisioning is great for Exchange 2010 because Exchange teams want to give their users enormous mailboxes (up to 25GB in some cases) and they don’t want to buy and allocate all of that space upfront. SATA with Virtual Provisioning is a great way to cut the cost of an Exchange infrastructure that used to demand those Tier 1 FC disks.
2. Slide 43 indicates EMC can only do EMC to EMC array replication. One nice surprise comes from EMC’s RecoverPoint product. It’s a journaling appliance that implements a write-splitter that sits on the host, SAN switch, or in the storage array itself. This replication appliance that splits the writes and keeps a copy in a local or remote journal and uses policy- driven bandwidth reduction and data compression technologies to shrink bandwidth significantly – sometimes by a factor of 5-10x. This is usually enough to justify the purchase of the product, due to the cost savings in bandwidth. Oh… so back to the main point… we have a lot of customers that use EMC storage at their primary site and another vendor’s storage in a secondary location. It’s heterogeneous. You don’t even need an EMC array and it works with FC or iSCSI protocols.
I’m hoping Denny doesn’t take this the wrong way – I learned a lot about what SQL DBA’s need to know after reading this… and I bet you can too. Remember to check out his PPT consider following him on Twitter and check out his blog here.