On Sun, 2006-01-01 at 12:44 -0800, Peter Gordon wrote: > On Sun, 2006-01-01 at 12:35 -0800, Florin Andrei wrote: > > It is a good policy to never exceed 80% usage on any partition, > > precisely for performance reasons. I am not certain how much each > > filesystem type (Ext2/3, XFS, FAT32) is affected, but 80...85% is a good > > number to keep in mind. Exceed it, and the performance usually starts to > > drop dramatically. > > Agreed in full. I generally make my partitions a lot larger > than I expect them to be used, for this very reason. Granted, it could > be easier for me, as disk space really *is* inexpensive where I live; > whereas it may not be in other areas... This is all good, but sometimes you do run out of space. I've seen several servers run out of space at night due to runaway processes or something similarly uncontrollable situation. Another possibility is large mailservers, databases, news spools or similar files that grow/shrinks/removes data in the middle etc. So IF a partition has gone over 90% you should expect a great deal of fragmentation, but no matter how bad it gets you cant just do a quick fixer-up since we have no online defragmentation program. I too see 250+ extents on binaries like /usr/sbin/mplayer, but that potential problem has been dismissed since ELF doesn't load the file up sequentially. (but readahead would have helped) Now, what I see as a bigger problem is my home directory.. A little excerpt: ./.evolution/mail/local/Inbox.sbd/Devel.sbd/linux-kernel: 1718 extents ./.evolution/mail/local/Inbox.sbd/Devel.sbd/Wine-devel: 1472 extents ./.mozilla/firefox/jajiw9vd.default/Cache/_CACHE_003_: 1150 extents ./.evolution/mail/local/Inbox.sbd/Devel.sbd/fedora-devel: 1139 extents ./.spamassassin/bayes_toks: 970 extents ./.evolution/mail/local/Inbox.sbd/Devel.sbd/linux-raid: 863 extents ./.evolution/mail/local/Inbox.sbd/Devel.sbd/fedora-users: 855 extents ./.mozilla/default/lxaxhxet.slt/Cache/_CACHE_003_: 777 extents ./.spamassassin/bayes_seen: 691 extents ./.evolution/mail/local/Inbox: 537 extents Now, I hope no one actually thinks this kind of fragmentation is just how it should be. True, I will survive even with this but I'd rather it wasn't. I've used this non-opensource util at a few occations, and had good results. Problems are: Not opensource, beta, offline-defrag. http://www.oo-software.com/en/products/oodlinux/index.html I would like to see an open-source defragmenter for ext3, if just for those worst-case scenarios. Fragmentation CAN happen, so there is a need for some. I'm posting this mostly to encourage those who might think of making an open source defragmenter. For the record, this system was installed using FC4 isos from scratch and has followed the stream of updates closely. -HK
