tar -u adds all files regardless of mod date

Gareth Bailey gjbailey at gmail.com
Fri Sep 9 02:00:00 PDT 2005


Hi there,

I have a directory I want to backup at /usr/dir_a/dir_b.
I want to back the content of this dir to /usr/backups/dir_b
so I tried the following:

# cd /usr/backups/dir_b
# tar -cf dir_b.tar /usr/dir_a/dir_b

Now I have dir_b.tar which is 65MB in size.
If i then try to update modified files by doing this:

# tar -uf dir_b.tar /usr/dir_a/dir_b

and I end up with dir_b.tar being 130MB (double size) which
should not be the case since no files have been modified in
 /usr/dir_a/dir_b.

I do not get this problem if I do the same in the /usr/dir_a
directory. In the /usr/dir_a dir the tar file remains the same
size.

I would much appreciate some input!

Thanks,
Gareth


More information about the freebsd-questions mailing list