Re: [Bug-tar] hard link extraction

[Joerg Schilling]

"Dustin J. Mitchell" <address@hidden> wrote:

> Over on the amanda-users list, we just had an interesting problem come up:
>   http://marc.info/?t=119261743100002&r=1&w=2
> to summarize, the user is running Cyrus, which makes scads of hard
> links.  On doing a restore of only a few files, tar fails because it
> doesn't find the antecedent of hard links.

If the archive was in the star dump format (POSIX-1.2001 + star incremental
dump extensions) you could extract the files with a trick:

star -c -dump MX2 | star -tv -find -ls -false 

Release     star 1.5a86 (i386-pc-solaris2.9)
Archtype    exustar
Dumpdate    1193068207.223226 (Mon Oct 22 17:50:07 2007)
Volno       1
Blocksize   20
6184490    0 drwxr-sr-x   2 joerg    bs             0 Jul 29 17:06 MX2/
6184495  134 -rw-r--r--   3 joerg    bs        136663 Jul 19 22:29 MX2/termcap
6184495    0 -rw-r--r--   3 joerg    bs             0 Jul 19 22:29 
MX2/termcap12345
6184500    0 -rw-r--r--   1 joerg    bs             0 Jul 22 12:38 
MX2/termcap12999
6184501    0 -rw-r--r--   1 joerg    bs             0 Jul 22 12:40 
MX2/termcap00999
6184495    0 -rw-r--r--   3 joerg    bs             0 Jul 19 22:29 MX2/termcap1
6184521    2 -r--r--r--   2 joerg    bs          1972 Jul 10 00:04 MX2/Makefile
6184521    0 -r--r--r--   2 joerg    bs             0 Jul 10 00:04 MX2/lM

-dump switches to the "exustar" archive format + dump extensions.

-find -ls -false uses find(1)'s ls code instead of the star listing so you see
the inode numbers.

As you now know the inode number for MX2/termcap (6184495) you could run:

star -cPM -dump MX2 | star -tv -find -inum 6184495
Release     star 1.5a86 (i386-pc-solaris2.9)
Archtype    exustar
Dumpdate    1193068476.685381 (Mon Oct 22 17:54:36 2007)
Volno       1
Blocksize   20
 136663 -rw-r--r--   3 joerg/bs  Jul 19 22:29 2007 MX2/termcap
      0 -rw-r--r--   3 joerg/bs  Jul 19 22:29 2007 MX2/termcap12345 link to 
MX2/termcap
      0 -rw-r--r--   3 joerg/bs  Jul 19 22:29 2007 MX2/termcap1 link to 
MX2/termcap

which only lists the file names related to the link. If you use -x instead of 
-t, the related files will all be extracted.

Could this help?

Jörg

-- 
 EMail:address@hidden (home) Jörg Schilling D-13353 Berlin
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