Backing up a FreeBSD system

[Rob]

Martin Schweizer wrote:
> Hello Steve
> 
> I copied once a week my filesystems /, /usr and /var to a second hard drive 
> with the following cron batch (it also mailed my the important files, fstab, 
> dmesg.boot and disklabes):
> 
> # Löschen der bestehenden Dateien
> /bin/rm /disk2/backup/*.dmp
> 
> # Dump wird erstellt. Wenn nicht erfolgreich (-> exit codes), 
> # wird ein Mail an your at isp.com versendet
> /sbin/dump -0au -f /disk2/backup/usr_$datum.dmp /usr || /usr/bin/mail -s Backup-Fehler your at isp.com

I see a risk here, in case dump fails: you're left with nothing.
Wouldn't it be better to do it in this order:

  /sbin/dump -0au -f /disk2/safe_backup/usr_$datum.dmp /usr
  <etc. etc.>

  if [ <successful> ]; then
    rm -rf /disk2/backup
    mv /disk2/safe_backup /disk2/backup
  else
    <send error message>
  fi

If the dump fails, you also get the error message, but now
the previous dump backup is still there!

Rob.