Thank you Richard, but my primary concern is that contradictory advice was published by IBM within a month. It is hard enough for us veterans, who started long ago with ADSM, to design efficient solutions for our customers. Having conflicting TechNotes from the IBM at minimum clouds the issue and at worst will lead some of the less seasoned astray. One of the TechNotes is wrong, or both are misleading. Which is it? Orville L. Lantto Glasshouse Technologies, Inc.
________________________________ From: ADSM: Dist Stor Manager on behalf of Richard Sims Sent: Sat 7/22/2006 07:40 To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] To DirMC, or not to DirMC Orville - Indeed, individual Technotes usually portray a small part of the big painting, and by the nature of their modest intention do not give a sense of the whole. Few customers use DIRMc, and depend upon the default behavior of storing directories with the longest management class Retonly value. That works well for most of us. But, then, we've seen the postings where retention policies have changed over time and directories are now missing such that the GUI is blocked in pursuing a path because it can't resolve that element. A missing directory entry is also not a good thing for rich data structure directories as found in Windows and Novell: while Restore Order processing will plant a skeletal directory in order to progress, that minimal entry is not what was in the file system originally, and may not fulfill needs after the restore. Another area of consideration in TSM directory storage is disaster recovery. With default storage, rich directories are "all over the place" in TSM storage. In disaster recovery, you may want to get one rich-directory client back into operation quickly, and in such case you may want to have its data set on a known, limited set of media. And, in any case, you don't want a restoral to go on for a protracted period, mounting tape after tape to locate directory entries within a larger collective. It is good that the evolution of the product has reduced the need for DIRMc; but we should be mindful of the circumstances which underly its purpose so as to not be blindsided when a high-profile recovery is needed. The mantra in our data assurance realm is "Plan for recovery". Richard Sims