UNIX for Dummies Questions & Answers

I am backing up some data to an NTFS formatted backup drive. I have to preserve the Unix permissions of the data being backed up and therfore use backup into a tar file.

I would like to backup the differnential data in the tar file similiar to how Rsync works so as to save on backup time as it currently takes a long time to do a full backup.

Can this be achieved using tar?

Thanks

Well... how about a combo of tar and ksh?

Create a list of the contents of your tar files at the time of their creation.
tar tvf tar_file > tar_info.dat
Compare the time stamp and/or size.
Modify the new tar list.

Then, when creating your list of files to include in tar, simply verify that the time stamp is different.

That is:

Code:

find . -type f -ls |
while a b c d e f g mon mday hours file_nm ; do

  nawk '$8==file_nm {print $4, $5, $6;}' file_nm=file_nm | read tar_mon tar_mday tar_hours

  if [[ $tar_mon != $mon ||
        $tar_mday != $mday ||
       $tar_hours != hours ]]; then
        print $file_nm
  fi

done >> new_tar_list

perhaps some tweakin may be in order.