Gardenia? Collocation directs TSM to store the data for a particular group of nodes, node, or filespace on as few volumes as possible. As Medhi Salehi noted, it keeps tape mounts to a minimum for restores, but it opens many more tapes.
In primary pools if you collocate by Node, each Client will open a tape and write to that tape until it is full. As long as MaxScratch has sufficient volumes, no other Client will use that tape. If you have 300 clients using that pool, you will have 300 filling tapes. Collocated storage pools will use more tapes and more tape mounts for processes that write to tape, whether that is backup-direct-to-tape or migrations from disk to tape. (Reclamation also honors collocation.) I am not sure if collocating a copy pool is beneficial. It seems like the copy pool as a disaster recovery pool would be ideal to collocate, but if you send off tapes every day you end up with a fragmented set of tapes for each collocation unit anyway. To clean that up would require bringing offsite tapes back onsite, exposing you to risk. It is possible to do a Move Nodedata in a copy pool, but the tapes have to be onsite. Perhaps there are better ways. Search this mailing list. There has been a lot of discussion about collocation's benefits and costs in the past. http://www.adsm.org/lists/html/ADSM-L/ http://www.adsm.org/lists/html/ADSM-L/2009-03/msg00263.html What are you trying to achieve with collocation? I hope this helps! -----Original Message----- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of gardenia28 Sent: Tuesday, November 24, 2009 12:37 AM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] collocation increases tape mounts while backup Hi, I find by applying collocation concept, the no.of tape mount increases while taking backup... Could anyone justify it or explain me why it is so? +---------------------------------------------------------------------- |This was sent by subhashinipanchaksha...@gmail.com via Backup Central. |Forward SPAM to ab...@backupcentral.com. +---------------------------------------------------------------------- IMPORTANT: E-mail sent through the Internet is not secure. Legg Mason therefore recommends that you do not send any confidential or sensitive information to us via electronic mail, including social security numbers, account numbers, or personal identification numbers. Delivery, and or timely delivery of Internet mail is not guaranteed. Legg Mason therefore recommends that you do not send time sensitive or action-oriented messages to us via electronic mail. This message is intended for the addressee only and may contain privileged or confidential information. Unless you are the intended recipient, you may not use, copy or disclose to anyone any information contained in this message. If you have received this message in error, please notify the author by replying to this message and then kindly delete the message. Thank you.
