Path: utzoo!attcan!uunet!mcvax!enea!kth!draken!tut!santra!kampi!alo
From: alo@kampi.hut.fi (Antti Louko)
Newsgroups: comp.unix.wizards
Subject: Re: GNU-tar vs dump(1)
Message-ID: <18762@santra.UUCP>
Date: 18 Jan 89 08:21:55 GMT
References: <17999@adm.BRL.MIL> <629@mks.UUCP> <11@estinc.UUCP> <10797@rpp386.Dallas.TX.US> <1966@netmbx.UUCP> <6099@polya.Stanford.EDU> <15@estinc.UUCP> <8768@alice.UUCP> <1989Jan17.044721.5636@utzoo.uucp>
Sender: news@santra.UUCP
Reply-To: alo@kampi.UUCP (Antti Louko)
Organization: Helsinki University of Technology, Finland
Lines: 35

In article <1989Jan17.044721.5636@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>In article <8768@alice.UUCP> debra@alice.UUCP () writes:
>>... if one renames a directory none of the
>>attributes of the files in this directory change. So the files are not
>>backed up and unless one knows the previous name of the directory one
>>cannot find the files in the backup again...
>
>This is why sensible backup programs know you must back up the contents
>of directories, not just files.  This isn't a miracle cure, but it helps.

And in my opinion, it doesn't help enough. Consider following:

mkdir /tmp/d; cd /tmp/d
mkdir d1 d2
echo This f1 is under d1 > d1/f1
echo This f1 is under d2 > d2/f1

Do level 0 gnu-tar dump of /tmp/d

mv d1 new-d2
mv d2 d1
mv new-d2 d2

Do level 1 gnu-tar dump of /tmp/d

Because level 1 dump doesn't contain any info that d1 and d2 were
swapped, and no times of f1:s were changed, restoring level 0 and
then level 1 gives you the situation after level 0 dump.

gnu-tar dump should contain the same inode-number info which is in
conventional dump(8) archives.
---
alo@santra.UUCP (mcvax!santra!alo)       Antti Louko
alo@santra.hut.fi                        Helsinki University of Technology
alo@fingate.bitnet                       Computing Centre