Richard, I would say you can do it good (TSM) or better as suposed by Orville. I do not see any reason why TSM should not take advantage of the mirrored disk's for db reading.
Regards Stefan Holzwarth > -----Ursprüngliche Nachricht----- > Von: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] Im > Auftrag von Richard Sims > Gesendet: Mittwoch, 25. April 2007 17:49 > An: ADSM-L@VM.MARIST.EDU > Betreff: Re: TSM only reads from COPY1 during DB backup > > On Apr 25, 2007, at 10:55 AM, Orville Lantto wrote: > > > Reads should be safe from mirrored volumes and are commonly done in > > operating systems to load balance. Not taking advantage of the > > available IO resource is wasteful and puts an unnecessarily > > unbalanced load on an already IO stressed system. It slows down db > > backups too. > > Then your issue is performance, rather than database voracity. > This is addressed by the disk architecturing chosen for the TSM > database, where raw logical volumes and RAID on top of high > performance disks accomplishes that. Complementary volume striping > largely addresses TSM's symmetrical mirror writing and singular > reading. Whereas TSM's mirroring is an integrity measure rather then > performance measure, you won't get full equivalence from that. > Another approach, as seen in various customer postings, is to employ > disk subsystem mirroring rather than TSM's application mirroring. In > that way you get full duality, but sacrifice the protections and > recoverability which TSM offers. > > Richard Sims >
