However, SANs make me nervous because they become a single point of failure. It is not unheard of for a SAN to go down or experience performances issues. A couple of examples that students have given me over the last while:
- A SAN firmware update (installed by the vendor while the vendor is onsite) wiped an entire SAN. Restore of all the SAN data from backup took 3 days.
- A SAN with unreliable cache disks. This results in downtime while the cache disks are replaced and poor performance until they are replaced. This has been an ongoing issue for this SAN.