Bill, The real question is, "what is your client data profile?" While I don't think I'd mirror a stgpool used solely for filesystem backups, I myself would be inclined to mirror a stgpool that contains "live data" such as archived txn logs from DB2 which then get reused or fileserver cleanup archive-delete processes. If, after either of the aformentioned data gets sent to disk, the disk fails before your daily (bi- or tri-daily? Somewhere in 8-24 hours, anyway) migration/backup, you could have a heck of an exposure.
For example, say, your DB2 backed up last night, and does more or less hourly txn log archives so that you can roll forward to the last instant (important for financial databases like SAP, so a failure would be very high profile). You backup stg and migrate disk to tape once in the morning, once in the evening. Your log archives at 5:30AM, gets moved to tape. DB2 archives again at 6:30, 8:00, 9:30, 10:30. However, after the 8:00 archive, the disk crashed and the volume went offline to TSM. Your next archives still succeed because they go to another disk volume or to nextstgpool. HOWEVER, they'll be useless. You can't meet your SLA and recover to point in time after 6:30AM because all your txn logs build off of the 8:00 one that is lost. Too bad you didn't mirror. 2nd example, say Accounting runs monthly financial reports. Your SLA says there's a 6 month retention on those reports, then they get archived (7 years, in case of audit) and deleted to save disk space on the fileserver. 6 months later, an automated script (because this is a well-defined process) goes to archive them and delete them from disk with an archive -deletefiles=yes. An hour later, before migration or backup stg happens, the disk crashes. Are you going to remember to restore from backup so that you can re-archive them, or is that data lost? Hope this helps you decide whether you want to mirror or not. Alex Paschal Freightliner, LLC (503) 745-6850 phone/vmail -----Original Message----- From: William Rosette [mailto:[EMAIL PROTECTED]] Sent: Friday, February 07, 2003 6:19 AM To: [EMAIL PROTECTED] Subject: PMR 02528, 082 Does any TSM gurus have any suggestions for our AIX admin Thank You, Bill Rosette Data Center/IS/Papa Johns International WWJD ----- Forwarded by Bill Rosette/IS/Corporate/Papa Johns on 02/07/2003 09:20 AM ----- Steven Schraer To: [EMAIL PROTECTED] 02/06/2003 05:09 cc: Bill Rosette/IS/Corporate/Papa Johns PM Subject: PMR 02528, 082 We are having some problems with the first link below. The second is working. I have been looking at the Redbook. Gettting started with Tivoli Storaage Manger: Implementation Guide. It looks like for storage pools are recommend for raid 0 (mirroring), raid 0+1 (mirroring & stripping) or raid 5 (distributed parity). These are safe methods to protect the storage pool. Do you know of any companies that use just raid 1 (stripping) on their storage pools? Is there an issue of tsm loosing a storage pool and the database having issues due to the lost storage pool data? Also there is no suggested raid for the tsm database. Since we mirror the tsm database with the tsm software, can we use raid 1 (stripping) so that we can get a performance increase on accessing the database? Or should we just create the volume group with no raiding but lay the database over multiple smaller disk (i.e. use eight 18.2 Gig disk instead of 4 36.4 Gig disk). What will give us the best performance. Can I get an answer on this tomorrow morning. I have a meeting to discuss the performance issues tomorrow (Feb 7, 2002). Thanks for your assistance! Steven M. Schraer 502-261-4148 ----- Forwarded by Steven Schraer/IS/Corporate/Papa Johns on 02/06/2003 04:57 PM ----- Bill Rosette To: Steven Schraer/IS/Corporate/Papa Johns@Papa Johns 02/06/2003 03:51 cc: PM Subject: PMR 02528, 082 Could not get into the link below. Thank You, Bill Rosette Data Center/IS/Papa Johns International WWJD ----- Forwarded by Bill Rosette/IS/Corporate/Papa Johns on 02/06/2003 03:53 PM ----- Stephen Hull <[EMAIL PROTECTED] To: [EMAIL PROTECTED] > cc: Subject: PMR 02/06/2003 03:36 PM Hi Bill, Here is a link to the Performance Tuning Guide on the web: ftp://w3.ibm.com/support/ats/documents/TSM42PDG.pdf Regards, Stephen Hull IBM Tivoli Storage Manager Support More questions? Search our new TSM KnowledgeBase at: http://www-3.ibm.com/software/sysmgmt/products/support/IBMTivoliStorageManag er.html
