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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msunews!agate!howland.reston.ans.net!Germany.EU.net!Dortmund.Germany.EU.net!nntp.gmd.de!news.ruhr-uni-bochum.de!news.rhrz.uni-bonn.de!RRZ.Uni-Koeln.DE!se From: se@MI.Uni-Koeln.DE (Stefan Esser) Newsgroups: comp.unix.bsd.freebsd.misc,comp.os.linux.hardware Subject: Re: Tape backup speed FreeBSD v. Linux Date: 31 Oct 1995 19:17:55 GMT Organization: Institute for Mathematics, University of Cologne, Germany Lines: 34 Message-ID: <475sp3$736@news.rrz.uni-koeln.de> References: <1995Oct30.090118.28117@state.systems.sa.gov.au> NNTP-Posting-Host: sysiphos.mi.uni-koeln.de To: chdemgt@state.systems.sa.gov.au Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:8206 comp.os.linux.hardware:20232 In article <1995Oct30.090118.28117@state.systems.sa.gov.au>, chdemgt@state.systems.sa.gov.au writes: |> This is a new Tandberg 1200S TDC4120 QIC-1000 tape drive. Being decoded, that |> is a SCSI-2 1.2 GB DC-600 quarter-inch cassette drive. It was bought for a |> FreeBSD system but the performance was disappointing. The computer (a |> 486DX4/100 with a Seagate SCSI-2 hard disk drive) also has a small Linux |> partition which can be booted with the help of a floppy disk. Here are the |> data rates on backup: |> |> 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. Well, there is quite some information missing ... 1) SCSI host adapter type 2) Backupp program used under FreeBSD and under Linux 3) Block sizes used (the defaults can be different, even if the same programs are used. I can keep my HP1533 DDS-2 DAT streaming easily, and it needs to be fed at 500KB/s to 1MB/s depending on file contents (compressible or not). Regards, STefan -- Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021 Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160 ============================================================================== http://www.zpr.uni-koeln.de/~se <se@ZPR.Uni-Koeln.DE>