2013/6/18 Colin Walters <walt...@verbum.org>: >> b/ let udevadm hwdb --update check, if /var or /var/cache is on a >> separate partition. > > If it was just udevadm, that wouldn't be so hard, but replicating > the (what I expect to be fairly fragile) code to detect /var's > paritioning scheme across any other components (e.g. fontconfig) > would be ugly. > > Though I do keep coming back to the hwdb being a special case, since > almost none of the other caches need to unify data from /usr and /etc. > > That does point out another potential solution - have two caches, one > in /usr and one in /etc, and the /etc one is only created if there's > anything to cache.
My very first idea was [1], to use /lib/udev for the cache file as long as /etc/udev/hwdb.d was empty. And as soon as files are added to /etc/udev/hwdb.d, the cache file is generated in /etc/udev and udev will first try to read the cache file from /etc and fall back to /lib This would be rather simple to add. The cache file in /lib/udev would still be perfectly shareable across hosts. And I don't share the concern that this would be confusing for users (and appear random). So I plan to use that approach in the Debian package. Fwiw, that is basically what you also initially suggested in [2], with the slight modification that you would use /etc/cache. The idea to have support for a split hwdb, where you can read fragments from different locations, is an interesting one. Dunno though, how much this would complicate the implementation. IIRC the hwdb cache/db file is mmapped. Michael [1] http://lists.freedesktop.org/archives/systemd-devel/2013-June/011383.html [2] http://lists.freedesktop.org/archives/systemd-devel/2013-June/011370.html -- Why is it that all of the instruments seeking intelligent life in the universe are pointed away from Earth? _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel