The big gotcha here is that you cannot use the simultaneous write feature if the backup is going lanfree.
________________________________________ From: ADSM: Dist Stor Manager [ads...@vm.marist.edu] On Behalf Of Kelly Lipp [l...@storserver.com] Sent: Monday, February 23, 2009 1:28 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] backups direct to tape Gill, I will start by asking: What do you think happens? The cool thing about TSM is it will usually do what you think it will do. If a tape error occurs, the current transaction (whatever it happens to be) will fail. What that means will vary. In the case of a client/agent backup, a write error on a tape will cause TSM to mount another tape and restart the failed transaction. Data integrity is the hallmark of the product. Direct to tape backups are actually cool. In fact, you can write two tapes simultaneously: the onlinepool and the drpool volumes. This avoids having to migrate data from disk to tape and having to back that data up. In the case of a 500GB database that will reduce the amount of data flowing through your server from 1.5TB to 500GB. Huge savings. And the write to two tapes happens at the same speed as to one. Kelly Lipp CTO STORServer, Inc. 485-B Elkton Drive Colorado Springs, CO 80907 719-266-8777 x7105 www.storserver.com -----Original Message----- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Gill, Geoffrey L. Sent: Monday, February 23, 2009 11:28 AM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] backups direct to tape I have a question that I hope those using TSM to back up direct to tape can answer. We don't, and never have, done this here and I'm not looking to implement it either. I am really looking for information as to "what happens to the backup" is a tape error occurs. (I just know I'm going to get this question when the dba's who have convinced everyone netbackup and direct to tape is so great) I am interested too if the TSM agents have the ability to compensate for this compared to a standard client backup. Will the agent take this into consideration and continue the backup with a different tape or will it die? The same question applies to the standard backup. Thanks for your help. Geoff Gill TSM Administrator PeopleSoft Sr. Systems Administrator SAIC M/S-G1b (858)826-4062 (office) (858)412-9883 (blackberry) Email: geoffrey.l.g...@saic.com
