Re: File system defragmentation. Something that can resume after stopping.

On 2026-05-14 12:30, Michael wrote:
> There's this archived paper from a 2007 Linux Symposium which explains how
> linux filesystems intelligently delay writing data to disk until the last
> moment so that data is allocated as contiguously as possible.  Also, after a

That (delalloc) is unfortunately not even half the story. XFS is still the only
filesystem (on Linux) that does persistent preallocation on regular writes,
and splitting the filesystem into multiple AGs (allocation groups) is much more
effective for *long-term* mixed-size free-space management than whatever ext4
does even today.

So while we're posting papers:
https://www.usenix.org/conference/hotstorage19/presentation/conway

Enjoy :)

-h