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Newsgroups: comp.unix.amiga,comp.unix.bsd.netbsd.misc Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!newsfeed.nacamar.de!news.nacamar.de!uunet!in3.uu.net!192.109.159.3!news.gtn.com!klicman.de!ora.de!bad From: bad@ora.de (Christoph Badura) Subject: Re: tar salvage? Message-ID: <E86w2o.46I@ora.de> Organization: Verlag O'Reilly References: <992.7033T1092T1352@ping.at> <slrn5kaeu3.avt.grr@shandakor.tharsis.com> <slrn5kb5it.r4.paul@wit387304.student.utwente.nl> Date: Sun, 6 Apr 1997 00:01:36 GMT Lines: 37 Xref: euryale.cc.adfa.oz.au comp.unix.amiga:15344 comp.unix.bsd.netbsd.misc:5751 In <slrn5kb5it.r4.paul@wit387304.student.utwente.nl> paul@wit387304.student.utwente.nl (Paul Boven) writes: >On 4 Apr 1997 17:36:11 GMT, George Robbins <grr@shandakor.tharsis.com> wrote: >>If the drive is one of the newer drives that write a special "end of medium" >>mark after the last data written on the tape and automatically rewinds when >>you stick in the catridge, there may be no practical way to get past the end >>of the tiny backup you created into the data you want. >Hey.. I've been trying for quite a while to stuff more than one >backup on a tape using the mt command, but it just made my tape go >forward, and then back again. Does anyone know whether a "st0 at >scsibus0 targ 4 lun 0: <WANGTEK, 5150ES SCSI FA00, 20> SCSI1 1 >sequential removable" would be prone to this end of medium misfeature? Since your tape drive is a QIC streamer, it is sort of "prone to this end of medium misfeature." And actually, it has nothing to do with whether the drives rewinds automatically when you stick in the cartridge. The problem with drives that write an "end of medium" mark is, that their firmware prevents you from reading anything past the "end of medium" mark. Companies doing data recovery have drives which don't have this restriction, hence you may be able to recover the data, but that isn't guaranteed. Of course, you loose the data that was overwritten with the "end of medium" mark. QIC drives are worse, though. If you start writing at track 0, they turn on the erase head and erase the data on *all* tracks. In this case, you can't recover the data. However, that has nothing to do with your problems. You should be using the "no rewind on close" device, i.e. /dev/rst0 for mt and your backups. -- Christoph Badura Now available in print: Lion's Commentary on UNIX 6th Edition, with Source Code http://www.peer-to-peer.com/