Re: backing up backups

[David Christensen <dpchrist@holgerdanske.com>]

On 4/10/22 22:15, tomas@tuxteam.de wrote:
> On Sun, Apr 10, 2022 at 09:44:59PM -0700, David Christensen wrote:
> > On 4/10/22 19:58, Default User wrote:
> > > Hello!
> > >
> > > My setup:
> > > - single home x86-64 computer running Debian 11 Stable, up to date.
> > > - one 4-Tb external usb hard drive to use as a backup device, labeled MSD1.
> > > - another identical usb hard drive, labeled MSD2, to use as a copy of the
> > > backups on MSD1.
> > > - the computer and all storage devices are formatted ext4, not encrypted.
> > > - two old Clonezilla disk images from when I installed Debian 11 last year
> > > (probably irrelevant).
> > > - Timeshift to daily back up system EXCEPT for data directories.
> > > - Back in Time to daily back up data directories.
> > > - Borgbackup to also daily back up data directories.
> > > - Rsync to frequently backup any changed data between the daily Back in
> > > Time and Borgbackup backups of data directories, using this command:
> > >
> > > sudo rsync -aAXHxvv --delete --info=progress2,stats2,name2 --exclude-from
> > > "/home/default/rsync_exclude_list.txt" /home
> > > /media/default/MSD1/rsync_backups_of_host_home_directory_only
> > >
> > > Each type of backup is in a separate subdirectory on MSD1 (Timeshift, Back
> > > in TIme, Rsync, etc.).
> > >
> > > It "seems" to work okay, BUT . . .
> > >
> > > Then I try to use rsync to make an identical copy of backup device MSD1 on
> > > an absolutely identical 4-Tb external usb hard drive,
> > > labeled MSD2, using this command:
> > >
> > > sudo rsync -aAXHxvv --delete --info=progress2,stats2,name2
> > > /media/default/MSD1/ /media/default/MSD2
> >
> >
> > See 'man 1 rsync'.  You have a slash at the end of SRC, but not at the end
> > of DEST.  I would add a slash after "MSD2":
>
> The only thing I find in rsync's man page about trailing slashes
> in the `dest' argument would be relevant if MSD2 didn't exist (in
> the OP's case it seems it does, no?)


There are four combinations for rsync(1) SRC and DEST vs. trailing 
slashes.  I use two -- trailing slashes on SRC and DEST for directories, 
and no trailing slashes on SRC and DEST for single files.  The other two 
combinations may "work" under certain circumstances, but they have 
caused me grief in the past and I avoid them as a matter of habit.


David