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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.rmit.EDU.AU!news.unimelb.EDU.AU!munnari.OZ.AU!spool.mu.edu!news.sol.net!newspump.sol.net!uniserve!n2van.istar!van.istar!ott.istar!istar.net!winternet.com!nntp.primenet.com!news.cais.net!bofh.dot!news.mathworks.com!tank.news.pipex.net!pipex!dispatch.news.demon.net!demon!awfulhak.demon.co.uk!awfulhak.demon.co.uk!not-for-mail From: brian@awfulhak.demon.co.uk (Brian Somers) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Wht does my dd to /dev/rsd1a claim it is read only? Date: 1 Jun 1996 00:13:36 +0100 Organization: Coverform Ltd. Lines: 43 Message-ID: <4onuf0$ld@anorak.coverform.lan> References: <31A4D266.41C67EA6@systemics.com> <4o6tdk$g5c@godzilla.zeta.org.au> NNTP-Posting-Host: anorak.coverform.lan X-NNTP-Posting-Host: awfulhak.demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Bruce Evans (bde@zeta.org.au) wrote: : In article <31A4D266.41C67EA6@systemics.com>, : Gary Howland <gary@systemics.com> wrote: : >I am running FreeBSD 2.1, and have two _identical_ (including the : >data) SCSI disks. I am trying to use one disk as a nightly : >backup, but the following commands fails: : > : > dd if=/dev/rsd0a of=/dev/rsd1a bs=4096k : > : >It fails with: : > : > dd: /dev/rsd1a: Read-only fileystem : > 1+0 records in : > 0+0 records out : The whole disk (or whole slice) device /dev/rsd1c contains a write : protected label in its second sector. /dev/rsd1a happens to overlap : /dev/rsd1c, so the write fails when it hits the label sector. : To copy the whole BSD slice, you could try : dd if=/dev/rsd0c of=/dev/rsd1c bs=4096k : but this should fail for the same reason. It might work if the target : slice is unlabeled (then the target device would have to be named : /dev/rsd1sN since c partitions don't exist on unlabeled slices). : To copy the whole disk, you could try : dd if=/dev/rsd0 of=/dev/rsd1 bs=4096k : This bypasses the write protection on the label(s) (this is a bug), : -- : Bruce Evans bde@zeta.org.au Or perhaps the problem is that you've booted single-user and have a read only root partition ? If this is the case, opening /dev/rsd1a to write will fail (I think ??!?). If so, "mount -u /" will help. -- Brian <brian@awfulhak.demon.co.uk> Don't _EVER_ lose your sense of humour....