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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.cis.okstate.edu!nntp.ksu.edu!newsfeeder.gi.net!news.mid.net!news.sdsmt.edu!data.ramona.vix.com!sonysjc!su-news-hub1.bbnplanet.com!cpk-news-hub1.bbnplanet.com!cam-news-hub1.bbnplanet.com!news.bbnplanet.com!howland.erols.net!newsfeed.internetmci.com!news.easystreet.com!not-for-mail From: tedm@agora.rdrop.com (Ted Mittelstaedt) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Tape file system Date: 27 Mar 1997 08:11:16 GMT Organization: Cool Dudes Inc. Lines: 23 Message-ID: <5hda34$6sk$2@easystreet03> References: <5h0pfc$7vg@fu-berlin.de> <5h454f$ii7@uriah.heep.sax.de> NNTP-Posting-Host: sunnet.portsoft.com X-Newsreader: WinVN 0.92.6+ Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:37814 In article <5h454f$ii7@uriah.heep.sax.de>, j@uriah.heep.sax.de (J Wunsch) says: > >> An other question is, why (or whether) lseek is not yet implemented >> like doing fast seeks as `mt fsr ...', any problems here? Should >> I just add an lseek system call for the st.c driver? > >No such thing like an lseek entry point to the device drivers. All >that lseek(2) does is to notify the upper layers that the next request >will go to a different address; this is in no way passed down to the >device drivers. All the device drivers see is that the next buffer >passed to the strategy entry point is on a different device address. > I'd love to have a tar that could seek to a specific block on the tape. I've got a number of QIC streamers I use at home for backup of stuff like /etc and friends, and they have advanced enough firmware to be able to go to a specific block on a single pass. Seeking for a file near the end of the archive is a real drag because the tapes saw back and forth forever getting to the file. What would be needed to be able to support the QFA commands of scsi tape drives?