Hi *SM'ers I am looking into why our LTO1 / LTO2 performance is so terrible (<50% rated throughput on avg) during backup stgpools.
TSM 5.2.4 AIX 5.2 IBM 3584 library LTO1 and LTO2 drives. The drives hit their rated throughputs during LANFree backup. We have 2 sites with the same devices, 3584 library with 12 LTO1 and 12 LTO2. Each site manages and clients to the others library, so siteA's copypools reside on volumes in the library managed by siteB and vice versa. We have 600MB/sec full duplex fibre connections between the two sites. This should cope with both sites using 6LTO1 and 6LTO2 to send copypool data to the alternate site at the same time. Max throughput from the drives shouldn't be more than around 550MB/sec During backup stgpools, I am told we are throwing approx 250-300MB/sec over the inter-site-link for the SAN. The drives at both sites appear to run at less than half the rated throughput. I have so far looked at movebatch and movesize, set to 1000 and 2048 currently. Performance under unix shows normal amounts of idle/user/cpu/iowait. Database cache hit% is 99.99 on a 120GB database. There is no log wait %. ....Does anyone have any pointers as to what to look through next? (I'm looking for quick wins; any very-in-depth investigations will require my borrowing a unix resource, and is complicated by the fact we have no test environment) One thing I am not sure of, are tsm internal data movements affected by the many-small-files scenario, or does this mainly impact dsmc backups? Some of the pools being copied hold millions of tiny files (300Bytes on avg) but not all pools. Thanks, Matt. [EMAIL PROTECTED] [EMAIL PROTECTED] http://tsmwiki.com/tsmwiki/MatthewWarren ___________________________ Disclaimer Notice __________________________ This message and any attachments are confidential and should only be read by those to whom they are addressed. If you are not the intended recipient, please contact us, delete the message from your computer and destroy any copies. Any distribution or copying without our prior permission is prohibited. Internet communications are not always secure and therefore Powergen Retail Limited does not accept legal responsibility for this message. The recipient is responsible for verifying its authenticity before acting on the contents. Any views or opinions presented are solely those of the author and do not necessarily represent those of Powergen Retail Limited. Powergen Retail Ltd is authorised and regulated by the Financial Services Authority for the sale and service of general insurance products. Registered addresses: Powergen Retail Limited, Westwood Way, Westwood Business Park, Coventry, CV4 8LG. Registered in England and Wales No: 3407430 Telephone +44 (0) 2476 42 4000 Fax +44 (0) 2476 42 5432
