|How to deal with very large backups|
Borg itself is great for efficiently de-duplicating data across successive backup archives, even when dealing with very large repositories. But you may find that while borgmatic's default mode of "prune, create, and check" works well on small repositories, it's not so great on larger ones. That's because running the default consistency checks takes a long time on large repositories.
A la carte actions
If you find yourself in this situation, you have some options. First, you can run borgmatic's pruning, creating, or checking actions separately. For instance, the the following optional flags are available:
borgmatic --prune borgmatic --create borgmatic --check
You can run with only one of these flags provided, or you can mix and match
any number of them in a single borgmatic run. This supports approaches like
making backups with
--create on a frequent schedule, while only running
expensive consistency checks with
--check on a much less frequent basis from
a separate cron job.
Consistency check configuration
Another option is to customize your consistency checks. The default consistency checks run both full-repository checks and per-archive checks within each repository.
But if you find that archive checks are too slow, for example, you can
configure borgmatic to run repository checks only. Configure this in the
consistency section of borgmatic configuration:
consistency: checks: - repository
If that's still too slow, you can disable consistency checks entirely, either for a single repository or for all repositories.
Disabling all consistency checks looks like this:
consistency: checks: - disabled
Or, if you have multiple repositories in your borgmatic configuration file, you can keep running consistency checks, but only against a subset of the repositories:
consistency: check_repositories: - path/of/repository_to_check.borg
Broken pipe with remote repository
When running borgmatic on a large remote repository, you may receive errors like the following, particularly while "borg check" is validating backups for consistency:
Write failed: Broken pipe borg: Error: Connection closed by remote host
This error can be caused by an ssh timeout, which you can rectify by adding
the following to the
~/.ssh/config file on the client:
Host * ServerAliveInterval 120
This should make the client keep the connection alive while validating backups.