Date: Tue, 17 Oct 2000 15:21:56 +0100 From: Daniel Bye <Daniel.Bye@uk.uu.net> To: 'Micke Josefsson' <mj@isy.liu.se> Cc: FBSD-Q <freebsd-questions@FreeBSD.ORG>, Odhiambo Washington <wash@iconnect.co.ke> Subject: RE: Defragmentation Message-ID: <FB7CAC781DB6D311BEE800805FE6FADA2F4CB4@camexch4.cam.uk.internal>
next in thread | raw e-mail | index | archive | help
Agreed. I have never seen anything above 3%, on a disk that has been hammered for months. I would only start to worry if disk usage were above, say, 80% AND I saw high fragmentation (above 5-6%). The work involved in taking a copy of the FS and rebuuilding disk setups (or manually copying and deleting files :o\ ) is too much to contemplate! I didn't know about tunefs, though, so thanks for that gem! Dan > -----Original Message----- > From: Micke Josefsson [mailto:mj@isy.liu.se] > Sent: Tuesday, October 17, 2000 3:20 PM > To: Daniel Bye > Cc: FBSD-Q; FBSD-Q; Odhiambo Washington > Subject: RE: Defragmentation > > > > On 17-Oct-00 Daniel Bye wrote: > > As far as I know, there are no defragmentation agents for > FreeBSD (or most > > other *NICES). Therefore, you would have to rebuild your > file systems. > > Take a tape backup of the entire system (this is sequential, so disk > > fragmentation is not an issue), rebuild your disk > slice/partition setup, and > > then restore the backed up file systems from the tape. > > > ffs tries to minimise fragmentation when writing files so > simply *copying* files > around should reallocate them with less framentation (then > delete the original > of course:). Moving files is not the same, as the actual > inodes must be moved > around for the system to get a chance of optimizing it. > > How many percent fragmentation is there? I have never seen > more than a couple of > percents worth. If the file system is full ffs will have a > harder time doing a > good job, in which case perhaps using tunefs to set size > optimization is a good > thing? > > > However, you shouldn't need to do this as often as under MS > systems, as the > > various UNIX file systems aggressively try to minimise data > fragmentation. > > > > If anyone knows of a defragmentation agent, I'd like to know :o) > > > > Never heard of it either. I don't think it is necessary. > > > ---------------------------------- > Michael Josefsson, MSEE > mj@isy.liu.se > > This message was sent by XFMail > running on FreeBSD 3.5-STABLE > ---------------------------------- > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?FB7CAC781DB6D311BEE800805FE6FADA2F4CB4>