Can anyone tell me how they defined their sequential FILE devclass and how the underlying hardware is setup? It seems like the best way to do this is to have multiple physical disks and spread the TSM volumes across the disks in a way to encourage spreading the i/o across the spindles. But because the devclass uses either the specified directory or the TSM default directory to build the volumes automatically then it appears you would be forced to either have a large software or hardware stripe or RAID volume or else an insane collection of storagepools to get enough space in the FILE volumes to make them usable. Maybe it is possible to manually create and checkin the FILE volumes so that I can create them in specific filesystems?
-----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Rushforth, Tim Sent: Tuesday, August 03, 2004 12:15 PM To: [EMAIL PROTECTED] Subject: Re: D2D vs. tape backups with TSM? I did some restore tests previously and found with my multi-session restore tests some of the restores were waiting for a long time for volumes that were in use. It was this that made me think that collocation was not good for this. At that point in time I was using 25 GB volumes, I've since switched that to 4 GB volumes. I just did a quick test - restoring 46.1 GB, 217,310 objects With no collocation, the data was spread across 36 volumes. With collocation it was spread across 14 volumes. No collocation restore and 8 mount points: 35.5 minutes, 22.2 MB/sec With collocation and 1 mount point: 68.9 minutes, 11.4 MB/sec With collocation and 8 mount points: 34.8 minutes 22.9 MB/sec So in my case as long as the data is spread out among a number of volumes (with collocation or not) multi-session restore works with a higher throughput than single session restore. So now I'm beginning to think that collocation may be good as long as the volume size is fairly small. My environment: TSM Server 5.22 on Windows 2003 TSM Client 5.229 on Windows 2003 The volumes are defined on SCSI disks (not ATA) Client compression is on It would be interesting to see what other people are experiencing. Thanks, Tim Rushforth City of Winnipeg -----Original Message----- From: Otto Schakenbos [mailto:[EMAIL PROTECTED] Sent: August 2, 2004 8:15 AM To: [EMAIL PROTECTED] Subject: Re: D2D vs. tape backups with TSM? Food for thought on multiple sessions and filebased backup: If you got 2(or more) virt. tapes on one disk(array) and the client has mounted them both and is pulling data from them this will probarly be slower in throughput then when just reading from one virt. tape at a time since sequantial reading is normally faster (esp. with ata) then random. In other words multiple mount points means the heads of your disk has to move longer distances then when using a single mountpoint. Thats why we have collocation turned on and only allow single sessions on our file type backup pool. maybe we are doing it all wrong anyway... regards Otto Schakenbos System Administrator TEL: +49-7151/502 8468 FAX: +49-7151/502 8489 MOBILE: +49-172/7102715 E-MAIL: [EMAIL PROTECTED] TFX IT-Service AG Fronackerstrasse 33-35 71332 Waiblingen GERMANY *********************************************************************************** 3/8/2004 This transmittal may contain confidential information intended solely for the addressee. If you are not the intended recipient, you are hereby notified that you have received this transmittal in error; any review, dissemination, distribution or copying of this transmittal is strictly prohibited. If you have received this communication in error, please notify us immediately by reply or by telephone (collect at 907-564-1000) and ask to speak with the message sender. In addition, please immediately delete this message and all attachments. Thank you. ACS
