Is there way to make squashfs images more friendly to adaptive updates?

[rmerrill-fw]

I'm guessing squashfs isn't very block-hashable because the on-disk format is not aligned on 4k boundaries in any way. Squashfs images that are nearly identical end up reusing almost no blocks. Is there a way to remedy this?

[jluebbe]

That's a trade-off with compression. By default mksquashfs uses 128kB blocks, which amplify any change.

The best way to handle this depends on why you choose to use squashfs for your filesystem. Can you share the background?

[rmerrill-fw]

Product that operates in remote locations with only a cellular connection. Update packages have to be as small as possible to avoid big cellular bills. Also, originally, space was much more constrained--we since got a big bump in our storage capacity.

I did end up answering my own question: If you use gensquashfs you can give the align attribute to files or globs of files, and this makes a pretty big difference.