Xref: utzoo comp.unix.admin:1730 comp.unix.questions:30995 comp.misc:12375 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!spool.mu.edu!uunet!mcsun!hp4nl!philapd!apdnm!atperf.idca.tds.philips.nl!pb From: pb@idca.tds.PHILIPS.nl (P. Brouwer) Newsgroups: comp.unix.admin,comp.unix.questions,comp.misc Subject: Re: Disc (De)Fragger Keywords: Disk Fragmentation Message-ID: Date: 3 May 91 10:22:53 GMT Article-I.D.: atperf.pb.673266173 References: <4973@syma.sussex.ac.uk> <1991May01.154043.1031@scuzzy.in-berlin.de> Sender: news@idca.tds.philips.nl Reply-To: pb@idca.tds.philips.nl (Peter Brouwer) Lines: 28 Organisation: Philips Information Systems, The Netherlands. Disclaimer: This opinion is mine alone In <1991May01.154043.1031@scuzzy.in-berlin.de> src@scuzzy.in-berlin.de (Heiko Blume) writes: >stevedc@syma.sussex.ac.uk (Stephen Carter) writes: >> Disc Fragmentation (etc) >for system V machines: >i regularly use a program called packdisk on my /usr/spool/news. >another program called fsanalyze tells me that the above filesystem >takes about two weeks to develop >40% fragmentation. packdisk makes >that ~3% again. packdisk was posted to comp.sources.misc, volume8, >fsanalyze is in volume5. of course packdisk is somewhat dangerous :-) This program has one disadvantage: It reformats the disk with a mkfs gap size of one. For most scsi disks this is okee but for ESDI this might result in a slow down of the diskthroughput. fsanalyze used the gap value from the superblock which is set to one by packdisk. So you will not notice it. If you are not sure if this is the correct gap value for your disk find a spare partition. Execute a mkfs with a gap of 1 . Use the bonnie disk benchmark to measure the disk throughput. Do this sequence for different gap sizes. The diskthrough put for sequential IO should give an optimum somewhere. -- # Peter Brouwer, | Philips Information Systems, # # NET : pb@idca.tds.philips.nl | Department P9000-i Building V2, # # UUCP : ....!mcsun!philapd!pb | P.O.Box 245,7300AE Apeldoorn,The Netherlands# # PHONE:ext [+31] [0]55 432992, | FAX :ext [+31] [0]55 433488 #