Hacker News Reader

It's been a while since I did that comparison, so the results could be significantly different now.

FWIW, I've updated the comparison using the latest versions of EROFS and DwarFS. There definitely have been improvements to EROFS in the meantime. DwarFS is still orders of magnitude faster in creating the file system and can achieve significantly better compression, but throughput is very similar unless you start optimizing the EROFS image for better compression.

Thanks ! One question though : why do you say "as it's pretty obvious that the domains in which EROFS and DwarFS are being used have extremely little overlap. DwarFS will likely never be able to run on embedded devices" ? (I mean : as far as I know EroFS was mostly used in smartphones, which are actually powerful devices !)

That's definitely a fair point! DwarFS actually works perfectly fine on 64-bit ARM and would likely work fine on a smartphone as well. Still (and I might be completely wrong about this), I think the primary goal of EROFS is to consume as little resources as possible when the file system is accessed and to be able to run on much less capable hardware, including 32-bit systems. DwarFS primarily cares about maximizing compression as long as it doesn't negatively impact performance (access times and throughput). This involves a certain amount of caching / pre-fetching and assumes there's plenty of memory available. This can be configured to a certain extent, but my pessimistic assumption is that DwarFS would use significantly more memory than EROFS. Might be worth actually backing this by numbers! :)

Reply on news.ycombinator.com