Fedora Constantine, SYSRQ and needless swapping

By default, fedora disables the SYSRQ functionality of the kernel, for some reason. To enable it, either add sysrq_always_enabled at the end of your kernel line in /boot/grub/menu.conf, or edit /etc/sysctl.conf, changing
[sourcecode language=’bash’]kernel.sysrq = 0[/sourcecode]
to
[sourcecode language=’bash’]kernel.sysrq = 1[/sourcecode]

Some kernel updates on fedora also have the tendency to write to swap needlessly, even though you have loads of RAM available, to stop this, edit /etc/sysctl.conf again, and add the following two lines
[sourcecode language=’bash’]# Controls the swapiness of the machine
vm/swappiness = 0[/sourcecode]
To just temporarily disable it, do
[sourcecode language=’bash’]echo -n 0 > /proc/sys/vm/swappiness[/sourcecode]
as root

***These tips are applicable to almost any GNU/Linux distribution, not necessarily for Fedora alone