I think if you defined some reasonable size of serial storage pools even on disk, that this would cut the fragmentation and still make it usable.
I wonder how fragmentation is handled if you use TSM to manage the disks as RAW instead of cooked with a file system on them? (Andy, any input?) -----Original Message----- From: Loon, E.J. van - SPLXM [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 02, 2004 4:15 AM To: [EMAIL PROTECTED] Subject: Re: D2D backup with TSM Hi Jim! > I know that this will involve running reclamation on the ATA storage pool but we felt using a DISK device class would waste to much storage because of fragmentation. Why did you think fragmentation was a waste of space? If a file expires, the space it allocated on a diskpool becomes free space, so it shouldn't be considered wasted. I can imagine that when a lot of little files expire, one gets a lot of fragmented free space, which could have impact on the specific disks performance in the long run. Funny to see that a lot of people (including us) are thinking about SATA storage for their backups. There doesn't seem to be anybody with real hands-on experience however... Kindest regards, Eric van Loon KLM Royal Dutch Airlines -----Original Message----- From: Jim Sporer [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 01, 2004 21:37 To: [EMAIL PROTECTED] Subject: Re: D2D backup with TSM We are going to try disk only backups using ATA storage. We've decided to use use a FILE device class for the ATA storage pool and do the backups directly to the ATA storage pool. We will back up the data to a copy storage pool defined on a 3494 tape library. I know that this will involve running reclamation on the ATA storage pool but we felt using a DISK device class would waste to much storage because of fragmentation. Jim Sporer University of Wisconsin At 10:05 PM 5/28/2004 -0400, you wrote: >We recently had a presentation from EMC. During this presentation >they discussed their new DL700 >virtual tape library. It got people talking about a long >term strategy of moving to a all disk based backup system. So we >started thinking of the pros and cons of how to go about setting up TSM >for a disk based backup system. > >Here are some initial thought on ways to configure TSM for D2D >backups. We would be very interested in your thoughts/comments. I >doubt we are the only people thinking about this topic. > >1)Purchase a very large disk system (ata drives?) and put storage pools on >them. > - use a standard DISK device pool for backups > - how to reclaim space? do you even need to? > - fragmentation problems? > - multiple node access concurrently > - use a FILE device based pool > - single node access per disk file volume > - need to run reclamation > - still stage to disk and migrate to FILE device based pool? > - use a tape copy pool for offsite and backup > - use a offsite disk pool somehow > - iscsi over lan or fc if close enough (enough throughput?) > - other? > - must use client compression to get data compressed > - we mostly don't do this today > >2) Purchase a virtual tape system like the DL700 > (bundle of a EMC Clariion and a FalconStor vts appliance) > - provides compression for data > - appliance is responsible for layout and use of disk space > - can copy a virtual tape to a real physical tape for offsite storage > > >Thanks > >Rick ********************************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. **********************************************************************
