Cleanup whitespace on partitions before compression
Posted in Operating Systems, Linux, Tips on Friday, December 6, 2013 by cam
Just a quick tip to help reduce the size of compressed partitions; particularly useful if imaging a drive for cloning etc. This tip comes from Bowen and Vagrant
apt-get clean -y
apt-get autoclean -y
# Zero free space to aid VM compression
dd if=/dev/zero of=/EMPTY bs=1M
rm -f /EMPTY
# Remove bash history
unset HISTFILE
rm -f /root/.bash_history
# Cleanup log files
find /var/log -type f | while read f; do echo -ne '' > $f; done;
# Whiteout root
count=`df --sync -kP / | tail -n1 | awk -F ' ' '{print $4}'`;
let count--
dd if=/dev/zero of=/tmp/whitespace bs=1024 count=$count;
rm /tmp/whitespace;
# Whiteout /boot
count=`df --sync -kP /boot | tail -n1 | awk -F ' ' '{print $4}'`;
let count--
dd if=/dev/zero of=/boot/whitespace bs=1024 count=$count;
rm /boot/whitespace;
# Whiteout swap
swappart=`cat /proc/swaps | tail -n1 | awk -F ' ' '{print $1}'`
swapoff $swappart;
dd if=/dev/zero of=$swappart;
mkswap $swappart;
swapon $swappart;