Posted Aug 18, 2009 5:49 UTC (Tue) by rawler (guest, #60308)
Parent article: The fanotify API
I can also see two relevant use-cases not mentioned here;
File-system-optimisation; While ext4 now have aquired defragmentation, I
still haven't seen any way in Linux other than the old tar/untar-way to
re-optimise files and directories for proximity to reduce seek-time.
(Say, for the apt/dpkg database). With this, it seems it would be
possible having a low-priority daemon tracking file-access-order, and on
system-idle (say, screensaver-time) simulate a tar/untar in frequent-
access-order to reorder them into better-on-disk positions.
Clutter removal; Now with the atime defaulting to relatime, it's getting
a bit harder to find old unused stuff, and wipe unused packages etc. This
new API should allow creating an ionice:d daemon with lax disk-queuing
track usage of files in the system, mapped to apt-packages, and track how
often packages are actually used. Given that accessing-process-info is
now also monitored, it may even be possible to prune indexers, grep and
friend from polluting the data. (By name, or by tracking access-patterns.
If something walks every file in a directory, we could probably ignore