How to set chunker parameters on init

[stroucki]

I want to experiment with rustic, and would like to know how to set up chunker parameters like min chunk size, max chunk size and average chunk size for a new repo. I wasn't able to find any documentation for this.

[aawsome]

Hi @stroucki! Thanks for the question!
This is currently hardcoded, i.e. you can only change it by modifying chunker.rs (see the constants in the beginning) and self-compiling your binary.
Note that also restic does not allow to customize this, i.e. if you run with your custom chunker, you'll loose deduplication if you have concurrent write-repo-access with restic or standard rustic.

[stroucki]

Thank you for the fast answer @aawsome. I am familiar with the issues of chunk parameter difference, and I am working in an isolated environment.

[aawsome]

After rustic-rs/rustic_core#422 you can now use
--set-chunker, --set-chunk-size, --set-chunk-min-size, --set-chunk-max-size on rustic init or rustic config to set the chunker (Rabin or fixed size chunking) and the size parameters.

This is already available on the nightly builds.

[repi]

is it possible to also set these options in your rustic.conf? that would be quite convenient

[aawsome]

@repi What do you mean by rustic.conf? There is no such config.
Note that you have to set the chunker parameters exactly once, when initializing the repository. Then they will be used by all rustic commands working on that repo.

[repi]

sorry I meant rustic.toml. something like this:

[repository]
repository = "local:c:/Users/repi/Backup/rustic-playground/rustic"
no-cache = true # not needed for local dir
chunker = "fixed_size"

so that when you initialize the repo you have all the settings from your config file that you may have shared or copied over, instead of only as explicit parameters to rustic init which is easier to miss.

[aawsome]

This is already available on the nightly builds.

If anyone reads this thread wondering when this will released: it is contained in v0.10.0

[aawsome]

sorry I meant rustic.toml. something like this:

[repository]
repository = "local:c:/Users/repi/Backup/rustic-playground/rustic"
no-cache = true # not needed for local dir
chunker = "fixed_size"

so that when you initialize the repo you have all the settings from your config file that you may have shared or copied over, instead of only as explicit parameters to rustic init which is easier to miss.

To clarify: No, the chunker options cannot be set in the toml profiles. They should be set preferably on rustic init.