From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Gill, Geoffrey L. >I was wondering if anyone was multiplexing backups to a single tape. >Recently I attended a Veritas class, our "other" new backup >system, (yes I >did ask to stay completely with TSM) and they really touted >this as what >seemed like a very good means of backup. Unless you have the >newer faster >technology tape drives I'm not sure I agree with it but don't have >experience since disk pools have always been plentiful. I'm >not sure I agree >with it anyway because I believe restores would be slow since >data would be >scattered throughout the tape. What if multiple restores need >the same tape? >Can they run at the same time and if so wouldn't that be even worse?
[sound of hollow laughter] Veritas doesn't tell you about the sting in the tail of their tape multiplexing. While it can make for faster backups, particularly with libraries with a small number of drives, they neglect to tell you that the de-multiplexing necessary to perform restores makes such restores considerably slower--as in (sometimes) an order of magnitude slower. ...and after all, I personally don't give a hoot about faster backups; it is faster *restores* I'm after. -- Mark Stapleton
