From: gilles@dgbt.doc.ca (Gilles Gagnon)
Subject: Re: Q: Poor person's backup
Keywords: backup
Reply-To: gilles@dgbt.doc.ca
Organization: The Communications Research Centre
Date: Fri, 6 Nov 92 20:46:58 GMT


Thanks to all those who sent me information on how to perform a backup
of a linux system. Following are the details I got regarding the possible
procedures one can use to backup his/her system when no tape drive is
available.

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From: Philip Perucci <dsc3pzp@nmrdc1.nmrdc.nnmc.navy.mil>

  To backup, get cpio.  Works GREAT.  I like the one DIRECTLY from the
  nice people at GNU, prep.ai.mit.edu (/pub/gnu).  The file is "cpio*"
  - just go to dir and do "dir cpio*" to get filename.  Down-load it,
  make it (yes...its clean!) and run it.

  To backup:  find X -print -depth | cpio -o -O /dev/fd0
              (where X = root directory of tree to backup)
  To restore: cpio -i -I /dev/fd0
  To examine
   contents
   of backup: cpio -it -I /dev/fd0
              (no files restored, just a list to CRT)

  Its beautiful:  You are prompted for floppies as required.  You can
                  get GNU cpio from a number of sites, I happen to 
                  favor the source.

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From gulasch!elmar@mcshh.Hanse.DE Wed Nov  4 18:31:00 1992

that's easy enough if you don't mind diskjockeying so many floppies.
I recommend using tar in conjunction with compress and, since this combination
can't write a multiple floppies archive, use one of the numereous disk-split
programs for that. The entire command would look like

	tar -c -v -z -f - | compress -c | diskbackup

where 'diskbackup' can be found on nic.funet.fi and, I think, tsx-11.mit.edu.
A few possible refinements:
- leave out directories you don't really want to save. For once, tar acts
  strange when processing /dev; other candidates might be /tmp and /usr/tmp
- when done, create an (empty) file to remeber the backup date
- invent sort of an 'incremental' backup where you only save files newer than
  that last backup (use find -newer)

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From dpg@cs.nott.ac.uk (Dave `geek' Gymer)

Well, various solutions have been proposed by lots of people using
various combinations of things like tar and cpio, and special programs
to split large files into floppy-sized pieces, but I've been using my
own port of the afio archiver (an extended cpio) for some time now.
afio provides multivolume archive support, and the ability to compress
individual files as they go into the archive (and, obviously,
uncompress them as they come out); this gives it a major advantage
over tar, since it can cope with corruption of individual files within
a large archive.  It's a sort of poor-man's version of ARJ for UNIX.

I've fixed quite a few bugs in the version of afio I'm using (I first
started using it about two years ago when I was using MiNT on and
Atari ST); one or two problems remain, but on the whole it is very
usable.

If anyone's interested, I'll be happy to send them the source.

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Yesterday I ftp'd, make'd and tried 'cpio' on my system. It worked fine
backing up a small subset of my system using the instructions given by
Philip Perucci. There was one little problem when I wanted to perform the
restore. The command 'find X -print -depth' lists the files within a
directory before listing the directory itself; this is the order in which
the files get backed up. This results, at restore, in cpio trying to
restore files in a directory which is not yet created. The directory
gets created after cpio tries to restore files. I could make it work
fine by removing the '-depth' option of find when performing a backup.

Now I will have to go buy a few boxes of floppies to perform a full backup
of my system. Lots of fun ahead :) .

BTW Maybe this information could be put in the next release of the FAQ to
    the benefit of people like me who want to perform backups but can only
    rely on floppies as their backup media.

PS. I now know that the diskbackup is mentionned in the FAQ ( I forgot to look
    first ). I think it would be good to mention the other options as well.

Thanks again everyone.

---
Gilles Gagnon     gilles@dgbt.doc.ca      | The Communications Research Centre
					  | 3701 Carling Avenue, Ottawa CANADA