We only back up 26 servers (NT, OS/2, Solaris, Linux, Mac) with one 3494 library and two 3590 drives. If we had collocation on our Copypool, it would mean sending 26 tapes off-site every morning, even if most of them had under a gig of data on them. All these tapes would then need to be reclaimed (we set the reclamation threshold to 60%) keeping our two poor tape drives permamnently busy. And, as we have a five day retention on our pending volumes, this means a potential 100 odd tapes floating about that we could be using.
We do collocate our Tapepool though to speed up restore times. Also, we don't have the five day pending problem with the on-site tapes. Farren - John Wiley & sons Please respond to "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] cc: Subject: Re: To Collate or Not to Collate? - UPDATE It depends on the size of your library too. We don't Collocate and we had a Disaster Recovery test and it was successful. We had time on our hand too with the 36 hours time limits David C. Pearson IS Production Support Analyst System & Network Service Snohomish County PUD # 1 -----Original Message----- From: Theresa Sarver [SMTP:[EMAIL PROTECTED]] Sent: Wednesday, January 15, 2003 12:25 PM To: [EMAIL PROTECTED] Subject: Re: To Collate or Not to Collate? - UPDATE Yikes! Okay, point(s) taken...Copypool set back to collate @ node level! Thanks again; Theresa >>> [EMAIL PROTECTED] 01/15/03 02:18PM >>> Hi, I fully agree. Specially after the experience of restoring one single destroyed tape in primary pool that implied mounting 85 copy tapes!! René LAMBELET NESTEC SA GLOBE - Global Business Excellence Central Support Center Information Technology Av. Nestlé 55 CH-1800 Vevey (Switzerland) tél +41 (0)21 924 35 43 fax +41 (0)21 703 30 17 local UBS-Nestec, Bussigny mailto:[EMAIL PROTECTED] This message is intended only for the use of the addressee and may contain information that is privileged and confidential. -----Original Message----- From: Cook, Dwight E [mailto:[EMAIL PROTECTED]] Sent: Wednesday, January 15, 2003 8:05 PM To: [EMAIL PROTECTED] Subject: Re: To Collate or Not to Collate? - UPDATE Allen makes a critical implied statement of YOU MUST TEST YOUR RECOVERY PLAN ! If not and you have to use it and it doesn't go smooth... Personally, I classify myself as probably being at the lowest place on the earth... and even if something were to initially miss me, it would undoubtedly/eventually settle on top of me! ! ! So... you request the test and state its requirement as to ensure functionality. If management says "no", make sure and put together a few things on what ~might~ go wrong like potentially 36 hours of nothing but tape mounts & dismounts to restore just a single server (if like in Allen's case where 800 tapes were required) Then make sure and save all the e-mails (print out and lock in a fireproof safe) so you can mount a defense later ;-) Dwight -----Original Message----- From: Allen Barth [mailto:[EMAIL PROTECTED]] Sent: Wednesday, January 15, 2003 12:31 PM To: [EMAIL PROTECTED] Subject: Re: To Collate or Not to Collate? - UPDATE Glad you found it! However, regarding the collocation=no issue on copypools.... Having done TSM DR recoveries at an offsite location a few times, let me share my experiences. When I started with TSM I had one copypool with colloc=no. We then did our first DR recovery test where my goal was to recover the TSM server and ONE other AIX client. The base os (AIX) was to restored via sysback, user filesystems via TSM. Originally this required the ENTIRE copypool (800+ tapes back then) to be sent from the vault to the DR location as TSM provides no command to see which vols would be needed for a client node restore (hint, hint, IBM). Since then I've been able to put an SQL query together to get that info but it takes quite a while to execute. This trims down the number of tapes, but the number of tapes was still quite large(100 +). Furthermore, the number of tape mount requests during the restore was astronomical, as tapes were requested multiple times. After re-thinking TSM and DR needs, I now have a separated stgpool tree for unix data. Collocation is enabled for both primary and copypools. At the last DR test, the number of tapes needed from the vault was further reduced to around 40, and the restore process took significantly less time. Let's not forget to factor in the time required for physical tape processing (mount delay, seek time, rewind, unload). This can add up to significant wall time. Regards, Al