What compression is used?

[mikael]

What zstd compression level does --max use? Also, can someone describe how --auto functions? Is it akin to what Borg’s auto does? Not finding a lot of details in the docs.

[MichaelEischer]

--compression auto uses the default compression level of the zstd implementation from klauspost/compress. (https://github.com/restic/restic/blob/ead8dd0173eb40b42de5ec9d23a10e6f2179a6a9/internal/repository/repository.go#L355). All data is compressed, there’s no distinction based on filetypes.

[mikael]

@MichaelEischer

--compression auto uses the default compression level of the zstd implementation from klauspost/compress .

Thanks! Does anyone know if --max and --auto offer higher compression than ZSTD-2 in TrueNAS Core?

@MichaelEischer

All data is compressed, there’s no distinction based on filetypes.

Good to know. It’s not the adaptive type that Borg (and soon TrueNAS) uses.

[rawtaz]

@mikael

Does anyone know if --max and --auto

There is no such option. You are talking about the --compression option to the backup command, which takes values max, auto and off.

[mikael]

@rawtaz

There is no such option. You are talking about the --compression option to the backup command, which takes values max, auto and off.

Sorry, typo. Meant --compression auto and --compression max. I still wonder about these settings compared to the TrueNAS levels though.