Last week, I was at the NetApp office in North Sydney for the presentation on NetApp SnapManager for Oracle. It was good opportunity to learn more about NetApp snapshots while working on a project for one of our clients in Sydney. It was an especially interesting topic as I have some experience using Veritas Checkpoints (see my presentation on test systems refreshes), and it was interesting to see what’s different and new in the NetApp implementation. But I digress.
I learned that NetApp can provide access to the same LUNs via either Fiber-Channel (FC) or iSCSI. And this is when the interesting argument surfaced. Apparently, some companies aim to have the technology stack on their disaster-recovery site as different as possible from the primary production site. Their argument is that if one technology fails at the primary site (like FC to access storage), then the DR site using a different technology stack will more likely be unaffected.
Hrm . . . I had never thought about this, and when I consider it now, it still doesn’t appeal to me. If I design a highly-available solution with a disaster-recovery site in place, one of my priorities would be to switch between the sites comfortably at any time. The more differences two sites have, the lower my comfort level is.
The only reason why I think some companies can “demand” having different storage technology stacks at production and DR is to justify a more convenient (a cheaper?) implementation.