On Thu, 2003-09-25 at 16:55, Scot Jenkins wrote: > you might try iostat (part of sysstat package) to see if disk io is > really an issue. Also look at top at the same time to see if the box is > hitting memory (shift+M to sort my memory) and/or cpu (shift+P to sort by > cpu) limits when the database performance is a problem. Thanks Scot. I'll play with this a little and let you know what I find out. > another thing to do would be to try see if a specific query is causing > the problem. Alot of times some poorly written sql is to blame for poor > performance. Joins on large tables or joins on too many tables will > really slow things down. you could try adding and "explain" to a query > to see what it's actually doing in mysql. > > Tom Penney wrote: > > My co worker is convinced that the ext3 partition hosting our mysql > > databases needs to be defragmented to improve lookup performance. I > > understand that fragmentation on ext2/ext3 file systems does not happen > > nearly as bad as it on fat32 or ntfs file systems. I've been told > > fragmentation is not a problem at all and ext3 File systems never need > > to be defragmented. I don't know if I believe that to be the whole truth > > because fragmentation does occur even if it's not really a big problem. > > > > I don't believe defragging this partition is going to make a noticeable > > difference but I don't really know for sure. The database, although it > > pretty big & flat, (~4Gig), it's pretty static. Not a lot is added to > > it. I have not yet run fsck on this partition to find out what the > > actual non-contiguous file count is. I have to take the box down to do > > that. > > > > Googling on the subject gets me to a lot of lug list archives of people > > voicing conflicting opinions but not a lot of solid info that was not > > over my head. > > > > I have these questions for you all. > > 1. Do you think defragging this partition is going to make a noticeable > > difference in performance? > > 2. Can anyone point me to any resources that would convince my coworkers > > that the problem is not the drive, it's the database? > > 3. Is backing up the partition, deleting it, then restoring the only way > > to deferment a ext3 partition? > > 4. is there a way to determine the how contiguous or fragmented one > > particular file is? > > > > Interesting article: > > http://www.informatik.uni-frankfurt.de/~loizides/reiserfs/agesystem.html > > > > -- > > Tom Penney <blots at visi.com> > > > > > > _______________________________________________ > > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > > http://www.mn-linux.org tclug-list at mn-linux.org > > https://mailman.real-time.com/mailman/listinfo/tclug-list -- Tom Penney <blots at visi.com> _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list