We run ours at 25% except one pool that we reclaim at 5%. Really, 5%. We ran incrementals direct to VTL with 30 servers backing up at one time, each to a separate virtual tape. Pool utilization was about 42% but %Migratable was at 93%. All those virtual 100 GB tapes with 1.2% utilization messed with the statistics. We had incremental backup failures when automigration kicked in. The data went to the secondary storage pool and we didn't have enough physical drives to handle the backup load. I used 'move data' commands to consolidate the data but instead of stacking data on used tape it started writing to recently-emptied tapes. We've reverted to backing up incremental data to disk and migrating to VTL.
More whining available upon request. Jim Schneider -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Andy Huebner Sent: Wednesday, June 04, 2008 9:47 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] VTL and TSM - Hyper Reclamation ???? We run ours at 50%. One thing to consider is whether your server and VTL will have the bandwidth to reclaim at those percentages. Andy Huebner -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Richard Rhodes Sent: Tuesday, June 03, 2008 8:08 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] VTL and TSM - Hyper Reclamation ???? We are investigating VTL's as a replacement for our 3494 libraries. A vendor was describing their sizing calculations and assumptions. One of their assumptions BLEW US AWAY!! The vendor recommended that reclamation be done on VTL volumes at a 20-30% Reclamation Percentage. YES, that's right, they recommend that a volume get reclaimed when only 20-30% of the data is expired. They claim that this is possible due to the efficiencies and speed of the VTL, and thus allow us to run at a much higher average utilization. The argument is that with a higher average utilization we can purchase less disk, and thus a less expensive VTL. Currently, for our tapes, we reclaim at 55-60%. Q) Has anyone every heard of performing reclamation at a percentage as low as 20-30%? Q) Is anyone with a VTL actually performing reclamation at 20-30%? Thanks! Rick ----------------------------------------- The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify us immediately, and delete the original message. This e-mail (including any attachments) is confidential and may be legally privileged. If you are not an intended recipient or an authorized representative of an intended recipient, you are prohibited from using, copying or distributing the information in this e-mail or its attachments. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete all copies of this message and any attachments. Thank you.
