Trouble with combined -G, -N options

[Jan Oberländer]

Hallo,

I am not sure whether this is the correct email address to report my
problems to, but I could not find other addresses and would thus be glad
if you could inform me about a proper address in case this is not the
one.

I'm trying to do an old-style incremental backup with tar, using -N to
store only those files newer than my time stamp.

The command I use is like this:

  tar --create -f /dev/nst0 -j -v -V "label" \
    -N /var/state/backup/ws.stamp -G /path /path2

However, the backup includes also files that are definitely older than
the time stamp -- it actually includes almost all files even if only a
few are newer than the time stamp.

Interestingly enough, there are still some files not backed up, but I
cannot tell the difference between these files, correctly backed up
files, and incorrectly backed up files.

Below are the stats of three files (names edited for simplicity); the
first is backed up though older than the timestamp (stats below). The
next two are not backed up - they are older too, so with those files tar
worked correctly.

So I actually have two questions:

1. Why are so many files that are older than the time stamp still backed
up? What am I doing wrong?

2. What is the difference between those files mentioned below that lets
one be backed up, but not the others? 

Note that I can not use --listed-incremental due to some peculiarities
in my backup hierarchy related to a limited tape size and the need for
unattended (except for tape changing during the day) backups. I do
level-0 backups in two parts - one tape contains /path, the other
/path2, with separate timestamps for the two parts. level-1 backups are
in two parts as well, operating relative to the level-0 stamps. level-2
backups, in turn, combine the two parts, operating relative to the older
level-1 stamp. If I can only solve my problem with --listed-incremental,
could you provide me with a solution on how to handle the timestamp
files generated by the -g option for this particular case?

I am using tar (GNU tar) 1.13.25 on Debian Woody.

Please let me know if you need more information. Thank you very much in
advance for your help.

Greetings,

Jan Oberländer

-- file stats below --

  File: "/path/to/file1-inbackup"
  Size: 593198          Blocks: 1168       IO Block: 4096   Regular File
Device: 812h/2066d      Inode: 1123873     Links: 1    
Access: (0660/-rw-rw----)  Uid: ( 1009/praktikant)   Gid: (  102/   
ccfa)
Access: Sat Feb 15 21:36:33 2003
Modify: Wed Sep 18 16:56:34 2002
Change: Wed Sep 18 17:33:24 2002

  File: "/path/to/file2-notinbackup"
  Size: 21609           Blocks: 48         IO Block: 4096   Regular File
Device: 812h/2066d      Inode: 32660       Links: 1    
Access: (0660/-rw-rw----)  Uid: ( 1009/praktikant)   Gid: (  102/   
ccfa)
Access: Sat Feb 15 15:37:11 2003
Modify: Tue Jul 28 21:16:14 1998
Change: Wed Sep 18 17:32:14 2002

  File: "/path/to/file3-notinbackup"
  Size: 124             Blocks: 8          IO Block: 4096   Regular File
Device: 802h/2050d      Inode: 455198      Links: 1    
Access: (0600/-rw-------)  Uid: (    0/    root)   Gid: (    0/    root)
Access: Sat Feb 15 23:08:11 2003
Modify: Sat Mar  9 16:17:02 2002
Change: Sat Mar  9 17:22:02 2002

  File: "/var/state/backup/ws.stamp"
  Size: 0               Blocks: 0          IO Block: 4096   Regular File
Device: 802h/2050d      Inode: 374629      Links: 1    
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: Sat Feb 22 00:30:04 2003
Modify: Sat Feb 22 00:30:04 2003
Change: Sun Feb 23 01:53:58 2003


-- 

+-------------------------------------+
| Jan Oberländer   <address@hidden> |
|          PGP key available          |
+-------------------------------------+