Bengt Richter <bokr@bokr.com> writes:

> I.e., isn't e.g. ext4 smart enough to defer actual allocation of physical page blocks
> when blocks are pure zero, and just store the fact of their existence in inode
> metadata?

Yes, ext4 supports that.

> Is there a version of df that has an option to output both sizes of
> a sparsely non-zero file?

I don't think df can do that, bu GNU `du' can, see the --apparent-size /
--bytes options.

-- 
Pierre Neidhardt
https://ambrevar.xyz/