Ubuntu Server 12.04.2 KVM Host Setup

#!/bin/bash
#KVM Virtual machine host package installation:

apt-get install ubuntu-virt-server

#set scheduler on all sd? devices

find /dev/ -name sd? -type b | cut --delimiter='/' -f3 | while read -r; do echo "deadline" > /sys/block/$REPLY/queue/scheduler; done && \
find /dev/ -name sd? -type b | cut --delimiter='/' -f3 | while read -r; do echo -n "$REPLY:";cat /sys/block/$REPLY/queue/scheduler; done

#configure default io scheduler to deadline
sed -i 's/GRUB_CMDLINE_LINUX=""/GRUB_CMDLINE_LINUX="elevator=deadline"/g' /etc/default/grub && sudo update-grub

#configure fstab mount options to relatime(assumes ext4 file systems)

sed -i -r 's/ext4(\s+)errors/ext4\1relatime,errors/g' /etc/fstab

#remount all filesystems with relatime using UUID
cat /etc/fstab | grep relatime | cut -f1 --delimiter=' ' | cut -f2 --delimiter='=' | xargs --verbose mount -o remount -U

#install NTP and configure to sync time with at least 2 local NTP servers if available

apt-get install -y ntp && service ntp stop
read -p "Enter IP/URL of primary time server:" primary_ntp_server && read -p "Enter IP/URL of backup time server:" backup_ntp_server
cat <<EOF >/etc/ntp.conf

driftfile /var/lib/ntp/ntp.drift
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable

server $primary_ntp_server iburst

server $backup_ntp_server
restrict -4 default kod notrap nomodify nopeer noquery
restrict -6 default kod notrap nomodify nopeer noquery
restrict 127.0.0.1
restrict ::1

EOF
service ntp start

#configure bridge networking with eth0 (assumes eth0 has static ip configured)

sed -i -e '/^[[:space:]]*#/!s/eth0/br0/g' -e '/^[[:space:]]*[^#]*iface br0 inet/a \
\tbridge_ports eth0 \
\tbridge_fd 9 \
\tbridge_hello 2 \
\tbridge_maxage 12 \
\tbridge_stp off'  /etc/network/interfaces

invoke-rc.d networking restart