*BSD News Article 91758


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.mel.connect.com.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!newsfeed.nacamar.de!fu-berlin.de!irz401!orion.sax.de!uriah.heep!news
From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: dump and compression
Date: 23 Mar 1997 19:42:38 GMT
Organization: Private BSD site, Dresden
Lines: 30
Message-ID: <5h413e$ii7@uriah.heep.sax.de>
References: <5glaem$io6$2@kayrad.ziplink.net> <5gma1u$icd@ui-gate.utell.co.uk>
  <y7zk9n5cgvk.fsf@hzsbc259.nl.lucent.com>
Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch)
NNTP-Posting-Host: localhost.heep.sax.de
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Newsreader: knews 0.9.6
X-Phone: +49-351-2012 669
X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F  93 21 E0 7D F9 12 D6 4E
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:37629

Peter Mutsaers <plm@lucent.com> wrote:

> Yes, and I think he's not alone with that problem. When I create tapes
> with tar I almost always use gzip to compress (-z flag to gnu TAR). It
> would indeed be very useful if dump/restore could do the same.

In particular, if dump would do it on a per file basis (per i-node,
more exactly), as opposed to applying it to the output stream.  This
way, if you encounter a medium error, only one file is lost, not the
remainder of the entire dump.

This should best be done by storing the filename with the .gz suffix,
and the file itself in standard gzip format.  This way, a restore that
doesn't understand compressed dumps would still be able to extract the
file, but just with a .gz suffix.  In order to trace which files have
actually been compressed by dump, and which were already .gz
originally, use a new flagbit.

This should not be very difficult using libz, but will bloat two
statically-linked binaries in /sbin.  However, piping through gzip
would be less optimal (you depend on additional binaries then).

``Just do it!'' :-)

-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)