Source: https://askubuntu.com/questions/963442/backup-ext4-data-to-exfat-partition
I advise you against using
rsync. You should use either
rdiff-backup, Duplicity, or Borg Backup.
rsync is great for mirroring – that is: syncing –
folders. You, however, probably want a backup. Imagine you accidentally
delete something, then your cron job starts a sync before you can stop
it. This means you just lost that data, even though you thought you had a
backup. But you only had a mirror. Now if you already made a copy of
that copy, you can get your data back as long as that's not already
overwritten, too. But if you don't notice your mistake for some time,
your data is lost.
Now, there is an rsync switch (
-b/
--backup) to prevent this. But you're probably still better off using a tool which is actually designed for making backups.
rdiff-backup is such a tool. It does, however, lack encryption.
Duplicity offers encryption. I did, however, make the personal
experience that it doesn't restore data reliably. That is, when I tried
to get a folder back to a previous state, the one file I really cared
about just wasn't restored. And I know that file existed before for
months because I just accidentally screwed it up, right before I wanted
to restore it. Duplicity wouldn't let me restore that file and when I
tried to get the folder back to various points in time, all of which I
would've been fine with because there were no major changes to that file
for months, it just didn't put that file in the restored folder and
didn't even print a hint indicating that that file was missing.
I don't know whether this is actually a problem with Duplicity or
whether it's a problem with Deja Dup as I used Deja Dup (which uses
Duplicity, which in turn uses
rsync, btw.) for backing up. I
did, however, try restoring the file/folder both via Deja Dup and
directly via Duplicity. It didn't work.
About half a year ago, a friend of mine asked me about how I do my
backups. The reason she asked me was because she experienced the exact
same problem with Deja Dup.
As my trust in Deja Dup was already gone after I experienced the
problem myself, I switched to Borg Backup, which I recommend you should
too.
Borg Backup takes a bit to get started on but once you know how it
works, it's great. It offers versioning, encryption, compression, and
deduplication. Backups with Borg Backup are faster than with Deja Dup
and you get to enjoy awesome features like being able to mount your
backup repository.
That is, you issue a mount command and then enter the location you
mounted your repository to. You will then see a list of backup labels as
folders. You can enter any one of these folders and look for your
files. No need to restore them revision by revision. They're just all
there in the mounted repo.
This means you can use normal command-line features and tools on
those revisions. For example, I recently found out that I accidentally
deleted my Firefox desktop file some time ago. Didn't notice for weeks. A
simple
ll */home/christoph/.local/share/applications/firefox.desktop
in the mounted directory gave me a list of all the revisions
containing that file. I simply copied the newest one out. But if you
wanted, you could take that list and do a diff on the results to see
what changed without having to restore anything first. Plus, mounting
and searching the repo was way faster than the time Deja Dup takes to
just figure out what file is gone.
If you use Borg Backup, it will actually keep track of ownership and
permissions without the file system in the backup location having to
support ownership or permissions as those are encapsulated by Borg.
Borg can be used perfectly well with cron jobs. It's just a single
command you need to issue. There is an archive name you need to specify
which needs to be a different one for each backup. If you issue the
commands by hand, you can write something more meaningful in there. I
simply use
date +%c for archive names because my backups are created automatically.
Storing your first backup on a FS with journaling is certainly a good
idea. As you then only create other backups and it's not terrible if
you have to throw the FS your 2nd backup is on away because it got
compromised when the power went out, using a non-journaling FS for it is
acceptable.
You can sync this second backup from the first one via
rsync.
There is no problem with this as you already made sure you can go back
to previous versions via Borg Backup, and – if you want – Borg already
took care of encryption, too.
