System Kernel

Kernel Parameter Tuning

vfs_cache_pressure

Influences the tendency the system reclaims memory for caching of VFS caches, versus pagecache and swap.

Temporary changes (until reboot):

/proc/sys/vm/vfs_cache_pressure

Do a permanent change (applied during reboot):

Either add a line to /etc/sysctl.conf or (better) create a new file in /etc/sysctl.d/*.conf.

If you use the second approach make sure that the filename starts with two digits and a hyphen (like 10-blah.conf). This is due the defined sequence for start-up.

• =0: The Kernel will never reclaim memory
• =100: Reclaim at a "fair" rate (= default)

Add a line in the config file:

vm.vfs_cache_pressure=40

Get detail information with sudo slabtop (dentry and *inode_cache are what we are looking for).

Additional ressources

• sysctl.d
• sysctl vm parameters

.bashrc

pacman autocompletion for packages not working

• but for everything else. Probably in this case the package bash-completion is already installed. *Comment-out the following line in .bashrc:

complete -cf sudo

Log-off and on again (source ~/.bashrc will not work here).