+Setup Xen within 20 minutes on Debian/grml
+
+Install relevant software und update grub's menu.lst (Xen does not work with
+usual lilo so install grub instead if not done already):
+
+apt-get install linux-image-2.6.18-1-xen-686 xen-hypervisor-3.0.3-1-i386 \
+ xen-utils-3.0.3-1 xen-tools bridge-utils
+update-grub
+
+Example for installation of Debian etch as DomU:
+
+mkdir /mnt/md1/xen
+xen-create-image --debootstrap --dir=/mnt/md1/xen --size=2Gb --memory=512Mb --fs=ext3 \
+ --cache=yes --dist=etch --hostname=xengrml1 --ip 192.168.1.2 --netmask 255.255.255.0 \
+ --gateway 192.168.1.1 --initrd=/boot/initrd.img-2.6.18-1-xen-686 \
+ --kernel=/boot/vmlinuz-2.6.18-1-xen-686 --mirror=http://ftp.at.debian.org/debian/
+
+Start services:
+
+/etc/init.d/xend start
+/etc/init.d/xendomains start
+
+Setup a bridge for network, either manually:
+
+brctl addbr xenintbr
+brctl stp xenintbr off
+brctl sethello xenintbr 0
+brctl setfd xenintbr 0
+ifconfig xenintbr 192.168.1.1 netmask 255.255.255.0 up
+
+or via /etc/network/interfaces (run ifup xenintbr to bring up the device then
+without rebooting):
+
+auto xenintbr
+iface xenintbr inet static
+ pre-up brctl addbr xenintbr
+ post-down brctl delbr xenintbr
+ address 192.168.1.1
+ netmask 255.255.255.0
+ bridge_fd 0
+ bridge_hello 0
+ bridge_stp off
+
+Setup forwarding (adjust $PUBLIC_IP; for permanet setup use /etc/sysctl.conf and
+add the iptables commands to a startup script like /etc/init.d/rc.local):
+
+echo 1 > /proc/sys/net/ipv4/ip_forward
+iptables -t nat -A POSTROUTING -o eth0 -s 192.168.0.0/24 -j SNAT --to $PUBLIC_IP
+iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to $PUBLIC_IP
+
+Adjust network configuration of Xend:
+
+cat >> /etc/xen/xend-config.sxp << EOF
+(network-script network-route)
+(vif-bridge xenintbr)
+(vif-script vif-bridge)
+EOF
+
+List domains, start up a DomU, shutdown later again:
+
+xm create -c /etc/xen/xengrml1.cfg
+xm list
+xm shutdown 1
+
+This HowTo is also available online at http://grml.org/xen/
+--
+Play tetris with zsh:
+
+autoload -U tetris
+zle -N tetris
+bindkey "^Xt" tetris
+
+Now press 'ctrl-x t'.
+--
+Set up a router with grml
+
+Run grml-router script:
+# grml-router
+
+Install dnsmasq if not already present:
+# apt-get update ; apt-get install dnsmasq
+
+Adjust /etc/dnsmasq.conf according to your needs:
+# cat >> /etc/dnsmasq.conf << EOF
+domain-needed
+bogus-priv
+dhcp-range=19.168.0.124,192.168.0.254,1m # dhcp range
+dhcp-option=3,192.168.0.1 # dns server
+dhcp-option=1,255.255.255.0 # netmask
+EOF
+
+Start dnsmasq finally:
+# Restart dnsmasq
+--
+Find out which process(es) cause the disk to spin up:
+
+# echo 1 > /proc/sys/vm/block_dump
+
+The command sets a sysctl to cause the kernel to log all disk
+writes. Please notice that there is a lot of data.
+
+See: $KERNEL-SOURCE/Documentation/laptop-mode.txt
+
+Also take a look at event-viewer(8).
+--
+Display stats about memory allocations performed by a program:
+
+Usage example for 'ls':
+
+% LD_PRELOAD=/lib/libmemusage.so ls > /dev/null
+--
+Use KVM (Kernel-based Virtual Machine for Linux):
+
+Make sure to install the relevant tools:
+# apt-get update ; apt-get install kvm
+# modprobe kvm