It's interesting to use the dump backup program if you want to take advantage of its several levels of backup procedures. Given below is a procedure to have a longer backup history and to keep both the backup and restore times to a
minimum. In the following example, we assume that the backup is written to a tape drive named /dev/st0 and we backup the home directory /home of our system.
It is important to always start with a level 0 backup, for example:
Where
-0 to -9 is the backup level option you want to use,
the u option means to update the file /etc/dumpdates after a successful dump,
The -f option to write the backup to file
The file may be a
special device file like /dev/st0, a tape drive,
/dev/rsd1c, a disk drive,
An ordinary file
the standard output.
Finally, you must specify what you want to backup. In our example, it is the
/home directory
/home.
You can see that we use the same tapes 2 to 5 for daily backups -Monday to Thursday = 4 tapes, tapes 6, 7, and 8 for weekly backups -other Fridays, 6 + 7 + 8 = 3 tapes. note that there
can be five Fridays in one month and tapes 1 and any subsequent new one for monthly backups -first Friday each month, 1 + any subsequent 11 months = 12 tapes. In
conclusion, if we use 8 tapes 4 + 3 + 1 = 8, we can have a full backup for one month and repeat the procedure with the 8 tapes to get our subsequent 11 months to come for a total of 1-year individual full backups.
The full backup should be done at set intervals, say once a month, and on a set of fresh tapes that are saved forever. With this kind of procedure, you will have 12 tapes for 12 months that handle histories and changes of your
system for one year. Later, you can copy the 12 tape backups onto a different computer designated to keep all yearly backups for a long time and be able to reuse them, 12 tapes, to repeat the procedure for a new year.
