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I'm new to crontab. Usually to make a backup, without crontab, I give this command:

cd /
sudo tar -cvpzf Ubuntu_17.04_ROOT_BackUp.tgz --exclude=/proc --exclude=/lost+found --exclude=/media --exclude=/Ubuntu_17.04_ROOT_BackUp.tgz --exclude=/mnt --exclude=/sys /

Now with crontab:

#Open and write to my_username's `crontab` file

$ sudo crontab -e -u my_username

# m h  dom mon dow   command
  25 13  * * * cd / && export DISPLAY=:0 && /usr/bin/tar -cvpzf Ubuntu_17.04_ROOT_BackUp.tgz --exclude=/proc --exclude=/lost+found --exclude=/media --exclude=/Ubuntu_17.04_ROOT_BackUp.tgz --exclude=/mnt --exclude=/sys /

Is this right? Would this schedule my backup?

Zanna
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IDK
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  • Why do you change directory to the root? Why not to a partition on an external drive (and exit with a loud complaint, if the external drive is not there); 2. Why do you export the DISPLAY variable? -- You can simplify the tar command line to backup only a small directory, so that it will be fast (within a few seconds), and then test in crontab with modified timing, for example * * * * * every minute) -- And when the test example works, you can set the time again to once daily or nightly and return to the complete backup in your tarcommand line.
    • – sudodus Sep 11 '17 at 13:04
  • The loud complaint (a sound or synthetic speech message) can be replaced by creating a file or appending a line to a log file, when there is an error and when the backup has started and when it has finished (let us hope without errors) . And then you can check that file from a terminal window, if you want to know the status of the backup. – sudodus Sep 11 '17 at 13:21
  • What you suggest seems cool, I'd like to do that, thing is I don't know how. For me is easier to create a backup in the root directory and then move it to my external hd then partitioning my external hd so that then I can back it up directly there. 2) The export command I added because of this https://askubuntu.com/questions/954723/crontab-issue-with-gedit and you lost me at the "loud compliant", like theoretically I know what you mean but in practice I got no idea.
    • – IDK Sep 11 '17 at 15:39
  • Also, I know that more directories and folders could be left out from the backup to make it faster but I' m not sure on which ones to left out, and is not so painful (takes about 15 minutes) . – IDK Sep 11 '17 at 15:54
  • If you have a fixed mountpoint for the external drive, you can simply use that as the target directory instead of the root directory /mountpoint-of-external-drive/backupfile.tgz; 2. OK, you want to see tar running in terminal window, and you want to write it to your graphical desktop. (I think most people let crontab jobs work in the background (with no terminal input/output.) ; 3. I meant just for testing that the crontab way to run the tar command works, you can let it do a very quick job, but never mind, it is not important, if you can wait for 15 minutes during the debugging.
    • – sudodus Sep 11 '17 at 16:42