3583 (and other LTO libs) is a "Speedy Gonsales" library in the Wintel world. Only Magstar 3590-E1A drives are faster. I would bet that your network is not so fast and direct-to-tape backup writes in small portions with pauses in between. So start/stop of tape consumes the main part of the time. Do the math by yourself - 100Mb Fast Ethernet ~= 10-11 MB/s (! make the difference between small "b" (bits) and capital "B" (bytes) !). Duplex does not count because you are not doing simultaneous restores with backups, aren't you. The LTO is capable of 15 MB native and 30 MB/s compressed. So the drive is up to three times faster than the LAN and you cannot use streaming mode features. As you point also backup to disk takes 3-4 min which gives approx. 4 MB/s. If this result is for many (i.e. small) files it is not so bad but for larger files you can get more (7 MB/s is a good target). So you can have a look at the network and client drives performance. On the other side 800 MB for 45s gives approx. 17.78 MB/s which is good. Use large enough disk pool for staging and everything should work fine.
Zlatko Krastev IT Consultant Gianni Garda <[EMAIL PROTECTED]> on 30.10.2001 12:19:27 Please respond to [EMAIL PROTECTED] To: [EMAIL PROTECTED] cc: Subject: 4.2.0 client backup performance Hi all, My scenario Running a TSM Server 4.2.0 on Win2000 with 3583 Library My problems is with performances backups of Win2000 Client (4.2.0). If the copy destination in backup copy groups is set to TAPEPOOL the performance is very bad (18 Min. for 800Mb). If the copy destination in backup copy groups is set to DISKPOOL the performance is good (about 3-4 Min) But the migration of 800Mb from TAPEPOOL to DISKPOOL is complete in about 45 seconds, so the write performance of the drive in library is good. I don't know why this difference . Any idea ? P.S. Sorry for my bad english. =========================================== Gianni Garda
