[Borgbackup] a couple of questions

[Draget]

Hey there, :-)

> The current stable is 1.10.

Just to avoid confusion: 1.0.10 (and very soon 1.0.11)

Your version 1.0.7 should do it's job just fine. But there have been a
lot of cosmetic / performance and mintor corner-case bugfixes. There is
no danger in just replacing it with 1.0.10, the backups will work the same.


> If you want “passphrase and having-the-key” security, use the keyfile
> mode. The key will be stored in your home directory (in
> .config/borg/keys). In the attack scenario, the attacker who has just
> access to your repo won’t have the key (and also not the passphrase)."

Small note: In keyfile mode you are responsible for keeping the keyfile.
Do not keep it on the PC you back up (since then it is gone when the PC
crashes as you cannot access you backup).

In most cases a repokey with a strong passphrase is the more sane choice.


>> Next question is: what happens if I close my laptop and put it to sleep,
>> or if I turn it off, and then run "borg create" again?
>>
>> Does it continue where it has been interrupted or does it start backup
>> all over again or something else?
> Have never tried it. Try it a see what happens?

Borg is explicitly desinged to take care of that! It creates a
'checkpoit' of it's index every 5 minutes (changable via
--checkpoint-interval). If you connection drops (or long hibernate) or
PC crashes while backing up, all chunks up to the last checkpoint will
be in the index.

You snapshot you tried to created in the repository will only be saved
as '<snapsotname>.checkpoint' and if you run the command again, borg
will skip all already known chunks, backup the rest and if successfull,
remove the old .checkpoint snapshot for you (if the name was the same).

So, you can happily interrupt your backup (if it ran for at least 5-10
minutes) and run it again until you managed to save everything. Perfect
for slow, initial backups over the internet.
(Note: Ofcourse, you should not nessecarily stress-test this feature by
forcing it a thousand times on your production-critical data… xD)


>> Next, what happens if I am using computer while it is backuping? For
>> instance, I am adding or deleting files?

Borg usues regular filesystem syscalls to walk though your files. If it
has not worked through directory X yet and you change something, borg
will backup this change once it is in directory X. The other way around,
borg will not notice any changes done to directories it already processed.

When working on a file WHILE borg is chunking it… it might cause locking
issues (borg will warn and skip it) or in the worst-case (if not
locked), it will store an inconsistent state.
It is your responsibility to avoid that.

Generally speaking, for a regular desktop-user this is a very rare case.
Most of the time programms lock their files or save them in a burst. And
even if, the next backup the consistent version will be saved.
So for regular desktop usage you will not have any issue in 99% of the
cases if you work while backup up - tho simply fix that by doing your
backup while you make a pause or at night. :-P


>> What if I change a file while it is being backuped? Example of this
>> would be, if I would be backing up VDI files (VirtualBox disks), which
>> are large (for instance 20 GB), and while VDI file is being backuped,  I
>> am using virtual machine and changing the content of VDI file?

For stuff like (active) virtual machine images (borg loves those,
deduplication is *great* on these) ofcourse the chance is a little
higher as they are constantly written to. Same with database files and
such. For critical data, you should make sure to have a consistant sate.
Dumps (DB-Dumps, VM-Snapshots) or on filesystem-level (btfs or zfs
snapshot) or on block level (lvm snapshot) for borg to work on.

(That being said, I have an active VM on my homeserver which I backup
'the wrong way' without snapshots or pausing it. Did one test and had
one actual restore - both times it worked without issues. Tho the data
is not exactly super-critical, that's why I do it. Sitll not
recommended. :P)


>> Unfortunately, I am not able to see the progress. I have opened the
>> issue, but cannot find an obvious reason for this behavior:
>> https://github.com/borgbackup/borg/issues/2419
>>
>> Are you planning to add some additional switch to show some kind of
>> progress indicator/status?

--verbose --progress… but I think this is one of the cosmetic things
that has been improved in newer versions. :-P



Happying backupping! :-)
Michael