Home directory on NFS (Network File System) with KDE might cause problems while desktop's IPC (Inter Process Communication) sockets are stored on networked disk and I/O-speed of network and storage itself doesn't match speeds that today's desktop systems can provide with local disk. This might appear as sluggishness and occasional hangups on the desktop.
Following the user's environment variables can be used to change where these different IPC-files are stored and point them into local disk. To make them system-wide for every user, each setting can be put into own file and dropped into /etc/profile.d directory to get included into user's login process.
XDG_CONFIG_HOME
XDG_CONFIG_HOME
File: /etc/profile.d/xdg.config.sh
if [ -d /srv/home/$USER/.config ]; then XDG_CONFIG_HOME=/srv/home/$USER/.config export XDG_CONFIG_HOME fi
XDG_CACHE_HOME
XDG_CACHE_HOME
File: /etc/profile.d/xdg.cache.sh
# could be more paranoid, and not accept any previously defined XDG_CACHE_HOME
if [ -z "${XDG_CACHE_HOME}" ] ; then
XDG_CACHE_HOME="/var/tmp/xdgcache-${USER}"
export XDG_CACHE_HOME
fi
if [ -d "${XDG_CACHE_HOME}" ]; then
# verify existing dir is suitable
if ! `test -G "${XDG_CACHE_HOME}" -a -w "${XDG_CACHE_HOME}"` ; then
# else, make a new/secure one with mktemp
XDG_CACHE_HOME="$(mktemp -d ${XDG_CACHE_HOME}-XXXXXX)"
export XDG_CACHE_HOME
fi
else
mkdir -p "${XDG_CACHE_HOME}"
fi
XDG_DATA_HOME
XDG_DATA_HOME
File: /etc/profile.d/xdg.data.sh
if [ -d /srv/home/$USER/.local/share ]; then XDG_DATA_HOME=/srv/home/$USER/.local/share export XDG_DATA_HOME fi
KDEHOME
KDEHOME affects where user's .kde directory is located and hence where those problematic socket files are located. Setting KDEHOME makes user's KDE settings machine specific which might be problematic in an environment where users move from desktop machine to another and expect to see the same, personalized desktop at each machine.
User's KDE IPC files under ~/.kde directory:
lrwxrwxrwx. 1 tuju tuju 22 Nov 5 2012 cache-wasa.netnix.ee -> /var/tmp/kdecache-tuju lrwxrwxrwx. 1 tuju tuju 26 Feb 2 15:47 socket-wasa.netnix.ee -> /run/user/500/ksocket-tuju lrwxrwxrwx. 1 tuju tuju 13 Nov 5 2012 tmp-wasa.netnix.ee -> /tmp/kde-tuju
File: /etc/profile.d/kde.home.sh
# cat USE_LOCAL_DATA.sh if [ -d /srv/home/$USER/.kde ]; then KDEHOME=/srv/home/$USER/.kde export KDEHOME fi
At the same time, while setting KDEHOME, user's .kde directory content should be moved into a newly created localhost home directory to avoid losing any KDE settings and application data.
KDEHOME contains directories like share/config and share/apps etc that should be considered user's data, not just mere dotfiles/settings and should be included into backup solution.
Disabling selinux permanently should be considered if new location does not match with default /home directory fcontext settings - which is most likely the case.
KDirWatchPrivate and Gamin
Attaching a gdb debugger intoa a hanging process with
gdb -p <pid>
and running a
thread apply all where
shows all threads. One of them might have:
Thread 1 (Thread 0x7fa8e1c56900 (LWP 25745)): #0 0x00007fa8db9ce460 in __GI___nanosleep (requested_time=0x7ffea3cef990, remaining=0x7ffea3cef990) at ../sysdeps/unix/sysv/linux/nanosleep.c:27 #1 0x00007fa8dc84b51d in qt_nanosleep(timespec) () from /lib64/libQt5Core.so.5 #2 0x00007fa8dde123c8 in KDirWatchPrivate::useFAM(KDirWatchPrivate::Entry*) () from /lib64/libKF5CoreAddons.so.5 #3 0x00007fa8dde1286b in KDirWatchPrivate::addWatch(KDirWatchPrivate::Entry*) () from /lib64/libKF5CoreAddons.so.5
that shows KDirWatchPrivate() class and it uses gamin (gamin provides /usr/lib64/libfam.so.0) and its notorious gam_server process. gam_server can be guided to two kind of modes for different directories, kernel notifications and polling. These can be set in /etc/gamin/mandatory_gaminrc file with
poll /net/* fsset nfs poll 10
where the last line might be enough to switch gamin monitoring to poll-method on NFS-shares. All these probably need a complete restart.
See also:
Commands
$ lsof -N -nP | grep kmail