Date: Fri, 2 Aug 2002 08:48:40 +0100 From: Matthew Seaman <m.seaman@infracaninophile.co.uk> To: Jonas Fornander <jonas@netwood.net> Cc: "'freebsd-questions@FreeBSD.org'" <freebsd-questions@FreeBSD.ORG> Subject: Re: Dump questions Message-ID: <20020802074840.GB51805@happy-idiot-talk.infracaninophi> In-Reply-To: <00ef01c239f2$f4333260$0800a8c0@master> References: <20020715221757.GB32811@happy-idiot-talk.infracaninophi> <00ef01c239f2$f4333260$0800a8c0@master>
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On Fri, Aug 02, 2002 at 12:05:15AM -0700, Jonas Fornander wrote: > If you dump a 50GB /usr file system that has only 2GB of files in it to > a second drive, does the second drive need to be 50GB too or can dump to > a 20GB drive? That should work fine --- dump doesn't create huge images of empty space, just the files, directories and metadata sufficient to recreate the filesystem. > Do I need to create directories on the second drive (i.e. dump_of_root, > dump_of_home etc..) or does dump create those automatically? It looks like you're trying to write out a dump archive as a file into a second filesystem -- so the normal rules for output to files apply. The path to the directory where you want to write your dump archive must exist. If what you're trying to do is replicate the filesystem to another drive, then you need to pipe the output of dump(1) into restore(1). I wrote quite a long piece about doing that in http://www.freebsd.org/cgi/getmsg.cgi?fetch=3471062+3475577+/usr/local/www/db/text/2002/freebsd-questions/20020630.freebsd-questions > When I try to dump / to a second drive, I get the following error: > #dump -0u -f /dev/ad2s1e / > DUMP: Date of this level 0 dump: Thu Aug 1 23:48:19 2002 > DUMP: Date of last level 0 dump: the epoch > DUMP: Dumping /dev/ad0s1a (/) to /dev/ad2s1e > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 61792 tape blocks on 1.59 tape(s). > DUMP: Cannot open output "/dev/ad2s1e". > DUMP: Do you want to retry the open?: ("yes" or "no") y > DUMP: Cannot open output "/dev/ad2s1e". > > I get the same error if I try to dump into a folder: > dump -0u -f /dev/ad2s1e/dump_of_root / > > Why can't dump write to the second drive? You seem to be getting the source and destination mixed up in the dump command. The file you output the dump to is the argument immediately following the '-f' flag: that should be a standard system filename in your case. (Other entries you may see commonly are '-' meaning write to the standard output or '/dev/nrst0' or the like, meaning write to a tape device.) The last entry on the dump command line is the filesystem to dump. That can either be a directory from a mounted file system, or the device file containing the filesystem you want to dump. In your case, you want to dump the root filesystem, which seems to be living on /dev/ad0s1a, onto a partition on your ad2 drive. Which means you need to create a filesystem on /dev/ad2s1e and mount it: newfs /dev/ad2s1e mount /mnt /dev/ad2s1e mkdir /mnt/dump_of_root dump -0u -f /mnt/dump_of_root/root.dump / umount /mnt This creates a file 'root.dump' containing an image of your root filesystem. Note that this sequence of commands will destroy anything previously existing on the /dev/ad2s1e partition. If you want to keep a regular series of backups on your other drive, omit the 'newfs' step, and label your output files by date: dump -0u -f /mnt/dump_of_root/root-`date +%Y%m%d`.dump / Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way Tel: +44 1628 476614 Marlow Fax: +44 0870 0522645 Bucks., SL7 1TH UK To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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