On Wed, Mar 07, 2007 at 09:58:09AM -0600, Kenneth Berry wrote: > Hello list, > > I have been working on a performance problem for about a month and I am > out of ideas. I hope someone can help me. What is happening is that > backups of large DLE that start very early seem to dump at a very slow > rate. Where as dumps of DLE on the same host, physical drive, etc. that > start hours latter dump at an expected rate. The amstatus snapshot > below was taken at 9:30:00. The backups start at midnight and notice > that the dump rate for mbthome:/home/public is about 830K/sec. But DLE > mbthome:/home_a_i which has been running for 21 mins. is at a dump rate > of about 9500K/sec. > > ------------------------------------------------- > mbthome:/ 0 51860k finished (0:32:54) > mbthome:/boot 0 8431k finished (0:29:27) > mbthome:/home/public 0 46747710k dumping 26966780k > ( 57.69%) (0:28:31) > mbthome:/home_a_i 0 20529050k dumping 11973280k > ( 58.32%) (9:09:34) > mbthome:/home_j_k 0 39011140k writing to tape (9:09:34) > mbthome:/home_l_o 0 13542210k wait for dumping > mbthome:/home_p 0 781310k finished (1:01:03) > mbthome:/home_q_z 0 10639260k wait for dumping > mbthome:/home_rest 0 10k finished (0:28:59) > mbthome:/usr 0 606581k finished (0:58:04) > mbthome:/var 0 330491k finished (0:38:43) > ------------------------------------------------- > > I have changed many things and not found the solution yet. I have moved > all the data from an hardware RAID5 to a single large drive on a > different SCSI controller. Played with maxdumps parameter it is set at > two for the above snap shot, for the data below the maxdump was set 1 > (default). Top utility shows very high CPU sys levels which settles > when dumps are finished, are mine higher than expected when amdump is > running?
Two things I'd look at, - are you using spindle #'s on your DLE to avoid multiple dumps from the same disk drive (in order to reduce thrashing) - /home/public is singled out among the /home group. Is it a different file system mounted there? Possibly a remote network mount? Is it greatly different in the type of data (lots and lots of small files or visa versa). Is it different in the dumptype from the other /home DLEs? -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 4455 Province Line Road (609) 252-0159 Princeton, NJ 08540-4322 (609) 683-7220 (fax)
