Richard, You have the same questions I had when I started to put in place our DR solution. We also have 3590E drives and I never tried to remove the hard drive default compaction. I don¹t see a reason for that. Now choosing software compaction is a must if you have enough cpu to do the work for backup and ALSO for restore. For us we can spend more time to use software compaction because we know that we have enough cpu to do the work at restore time offsite. The gain at restore justifies to take more time at backup processing. It¹s true too that software compaction takes less tapes than with no compaction. If you have many dasds to backup and a time constraint to restore i would suggest you to both use hard and software compactions. Our idea is to say that when we restore in a DR test the cpu is used ONLY for restore. Why not fully using it !
Regards Alain Benveniste Le 29/04/09 20:46, « Schuh, Richard » <rsc...@visa.com> a écrit : > We are working on a DR process. I notice that the defaults for a Hidro backup > include the PACK option which tells Hidro to pack, or condense in some > fashion, its output. The output is being written to 3590E drives. It appears > that there are three choices we can make for condensing the data: software > only, hardware only, or a combination of the two (uncompacted was purposely > omitted from the list). Which is likely to give the best results? Does > software compaction produce consistently lower output volumes than letting the > drive do it? Is there anything to be gained by using both h/w and s/w? > Obviously, software compaction costs in terms of cpu time. The question is, is > it worth the time spent? > > Regards, > Richard Schuh > > > >
