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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.rmit.EDU.AU!goanna.cs.rmit.EDU.AU!munnari.OZ.AU!news.ecn.uoknor.edu!paladin.american.edu!europa.chnt.gtegsc.com!news.kreonet.re.kr!usenet.kornet.nm.kr!agate!howland.reston.ans.net!Germany.EU.net!news.dfn.de!RRZ.Uni-Koeln.DE!news.cologne.de!usenet From: Wolfgang Stanglmeier <wolf@dentaro.Cologne.DE> Newsgroups: comp.unix.bsd.freebsd.misc,comp.os.linux.hardware Subject: Re: Tape backup speed FreeBSD v. Linux Date: 9 Nov 1995 00:18:12 GMT Organization: Cologne Net e.V. Lines: 28 Message-ID: <47rhc5$972@fileserv1.cologne.de> References: <1995Oct30.090118.28117@state.systems.sa.gov.au> <47ng5h$4ln@pacer.apana.org.au> NNTP-Posting-Host: dentaro.cologne.de Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 1.1N (X11; I; BSD/386 uname failed) X-URL: news:47ng5h$4ln@pacer.apana.org.au Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:8432 comp.os.linux.hardware:20669 john@pacer.apana.org.au (John Saunders) wrote: >chdemgt@state.systems.sa.gov.au wrote: >> Claimed by Tandberg in the spec: 12/18 MB/min >> FreeBSD 951020 SNAP: 9.1 MB/min >> Linux 1.2.x (forget exactly): 15.4 MB/min >> The something was wrong could be detected at once by ear. On FreeBSD the tape >> seems to run forward for 1.5 sec and then back for 1.5 sec. This continues >> without intermission during the backup. On Linux the tape seems to run >> forwards for long periods of time, very occasionally reversing once. >It seems as though FreeBSD can't provide the drive with data fast enough to >keep it streaming. So the drive stops and must backup in preperation for the >next lot of data it receives. I took the logs of my last backup (3 partitions of a HTTP/NEWS/MAIL Server). i486/66 PCI SCSI/NCR53c810 HP-DAT. : 22282240 bytes transferred in 46 secs (484396 bytes/sec) : 924450816 bytes transferred in 1453 secs (636235 bytes/sec) : 902561792 bytes transferred in 2011 secs (448812 bytes/sec) This results in 29, 38 and 27 Mb/min. I guess FreeBSD isn't the limiting factor. Bye Wolf