@sun @maija @meeper theres still open tickets about using zstd

i'm kind of mixed because zstd is a rather large code blob. you can get close to the same performance with RoLZ with huffman tables slapped on*, and the whole ordeal is <5k SLOC. but as far as i know there isn't like a helpful deployable lib for that (there is 'orz' in rust but its kind of just done as a concept.)

i think you could do what they are doing with fastcdc (to chunk up images), a chunk store, and maybe an sccs weave to store the chunklist for revisions, though i dunno if rolz'ing up individual chunks would be useful (borg et all do this but it does kind of lose inter-chunk rendundancy stuff at the LZ layer), although a chunk store does require stash space and one of the big deployments of ostree is to shove OTA updates for embedded ewaste