|1. Should disk and tape devices be attached to different HBAs?|
|2. If yes, why?|
|3. If no, why?|
There's a mini debate among storage area network (SAN) architects about whether or not to keep disk and tape devices on separate SANs, i.e., attached to different HBAs. Apparently, the majority (73%) of Storage magazine readers err on the side of more HBAs, rather than less. Why? There are a number of reasons--not least of which are performance and stability concerns. As author and analyst W. Curtis Preston explains, "Tape requires much more maintenance than disk," and errors from a tape library often cause a host bus adapter (HBA) to reboot. Keeping disk and tape on separate HBAs can minimize this problem. On the other hand, many readers forgo separate HBAs too, most often in the name of keeping things simple and costs down.