Do docker containers have to be shutdown for Restic to back them up?

[rawtaz]

@Imitate8184

Applications and Docker are the same so not useful to think of them as different things

No, Docker is a software that basically orchestrates security and isolation features in e.g. a Linux system such that you get the concept of containers running. Sure, Docker is an application, but applications does not by definition have the same features or traits as Docker just because both of them are applications.

@Imitate8184

If you application has an external db then try to do a dump of your db prior to doing the backup and let restic back that up

It boils down to what database we’re talking about. Some databases can be backed up straight away, some you should dump or similar before backing them up.

@Imitate8184

a. Question: Here I would imagine doing a dump of your db means you don’t have to turn off your container?

Correct, because you can dump the database while the database server is running.

@Imitate8184

b. Question: Should the db dump lock the db first to prevent writes, you think?

Depends on what database it is and what contents it has, but generally speaking this should be handled as part of the dump, yes. See the man page for the software you use to dump the database before backing up.

@Imitate8184

c. Photoprism, Nextcloud, Ghost, or FreshRSS seem like good examples here maybe?

Examples of what? Neither of these are databases as far as I know.

@Imitate8184

If you application has a sqlite then you don’t have to turn off your container and just make sure you are backing that sqlite as part of the application folder (i.e. docker bind mount)

Your SQLite database is nothing but a file in the filesystem (be it on the host filesystem and bind-mounted into a container, or in a volume, or whatever). Yes you should be able to back that file up straight away.

@Imitate8184

If your application isn’t really doing a lot of reads and writes then maybe you don’t have to turn those off neither do you have to worry about a db.

Indeed, if you deem that you have such low activity, e.g. at certain times, then you might get away with just backing it all up straight off the bat. But then again, there’s no reason not to do it the safer way, just in case.

@Imitate8184

Do you know how filesystem snapshots here help?

Snapshots can be used to keep a filesystem consistent for e.g. backing up the snapshot. But this does not mean that the data in your database and/or files was consistent at the time that you took the snapshot, so it’s not really a replacement for looking at the applications you have running and architecting your backup procedures to take these into account.