I have found on some large disk pools, that is say, 5x the size of a tape, we set migration to continue to yes, set the high level to 20, and low to something like 3 to 5 percent. Yes, I do daily 'flush' the pools by setting them to hi=0, lo=0 for a while before I do a db backup.
Why 20% for high? If the pool gets that much migratable data, it can fill a tape. This way as a tape of data is ready to be migrated, it can pretty much stream from disk to tape without waiting for additional data. I have thought of making it 10% or half a tape worth, but I don't know if I will gain much from it other than spinning tapes a little more often. Oh yes, in the mornings, I do build my copypool tapes from disk data first, before backing up my on-site tape pool. -----Original Message----- From: Mr. Lindsay Morris [mailto:[EMAIL PROTECTED] Sent: Monday, June 23, 2003 8:45 AM To: [EMAIL PROTECTED] Subject: Re: How to query if there is data to migrate for a primary storage pool?? I think most people use server scripts (or the older way, admin schedules) to set migration up and down daily. Why are you using shell scripts? Typically you'll write a server script that does most of the daily housekeeping jobs, one after the other, and one admin schedule to fire it up at 6 AM. And in more direct answer: I don't think you need to care about whether there is data to be migrated or not. Just set the himigration point down (not quite to zero) once a day to kick off migration, then set it back up (not quite to 100%) to discourage migration at might. ----------------------------- Mr. Lindsay Morris Lead Architect www.servergraph.com 512-482-6138 ext 105 > -----Original Message----- > From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] Behalf Of > Lawrence Clark > Sent: Monday, June 23, 2003 8:55 AM > To: [EMAIL PROTECTED] > Subject: Re: How to query if there is data to migrate for a primary > storage pool?? > > > Not sure what your asking, but > > Select * from stgpools > > will give you stgpool data in total. > > >>> [EMAIL PROTECTED] 06/21/03 05:28PM >>> > Hi, > > Is there a SQL query example, that shows how we can determine if a > storagepool has qualifying data that can migrate .... > > We have a shell script the lowers the thresholds (higmig=1, and > lowmig=0) to force a migration..... and waits... eventually timing out, > or finding a completion message... > > I was hoping there was a way to determine if we should even try to do a > migration, to save lots of looping and sleeps in our shell scripts.. > > Any suggestions would be appreciated.. > > Thanks, > > Steve Taylor >
