Virtual machine images tend to grow over time, causing exported machine images to be unnecessarily large. Here’s how to remove the excess baggage.
Step 1. Delete temporary files and unneeded log files
The following commands will remove temporary files and cached packages from various package managers. There is certainly more that can be done, but these are a few steps.
Another easy location is the system log files. Manually review /var/log and remove unneeded files.
find /tmp /var/tmp -mindepth 1 -maxdepth 1 -exec rm -rf \{\} \;
# Red Hat, CentOS
sudo yum clean all
# Debian, Ubuntu
sudo apt-get clean
sudo apt-get autoclean
# Arch
sudo pacman -c
Step 2. Boot VM with Parted Magic ISO
- Download Parted Magic Live ISO.
- Connect the VM CD/DVD drive to Parted Magic ISO, and select the connect at power on box.
- Configure the VM to boot from CD
Step 3. Zero unused disk blocks
In Parted Magic, Open a terminal instance
# if using LVM, activate devices vgchange -a y # for each partition containing an ext* filesystem, run zerofree: fdisk -l | grep dev zerofree -v /dev/sda1 zerofree -v /dev/sdb1 zerofree -v /dev/sdc1 zerofree -v /dev/sdd1 zerofree -v /dev/mapper/VolGroup00-LogVol00 # for swap partitions, zero then recreate swap dd if=/dev/zero of=/dev/<swap device> bs=1M mkswap /dev/<swap device> #NOTE: This will create a new UUID. If your /etc/fstab file uses UUID rather than device paths, you will need to update the swap entry in /etc/fstab with the new UUID. mount /dev/<Root Device> /mnt vi /mnt/etc/fstab
Shut down the VM
Step 4. Shrink VMDKs
SSH to your vSphere/ESXi server. If you don’t have SSH enabled, look here: How to enable SSH on vSphere
# change directory to your VM. Replace <VM> with the name of your VM. cd /vmfs/volumes/datastore1/<VM> ls -lah *.vmdk -rw------- 1 root root 80.0G Sep 11 18:53 vm-flat.vmdk -rw------- 1 root root 506 Sep 11 18:32 vm.vmdk -rw------- 1 root root 40.0G Sep 11 18:53 vm_1-flat.vmdk -rw------- 1 root root 506 Sep 11 18:53 vm_1.vmdk -rw------- 1 root root 10.0G Sep 11 18:53 vm_2-flat.vmdk -rw------- 1 root root 506 Sep 11 18:53 vm_2.vmdk -rw------- 1 root root 20.0G Sep 11 18:54 vm_3-flat.vmdk -rw------- 1 root root 506 Sep 11 18:53 vm_3.vmdk #for each vmdk, skipping the "-flat" files vmkfstools --punchzero vm.vmdk vmkfstools --punchzero vm_1.vmdk vmkfstools --punchzero vm_2.vmdk vmkfstools --punchzero vm_3.vmdk
Step 5. Optional: Export VM
Your VM should now be thin provisioned, using the minimum space in your datastore. You can now export using vSphere Client or ovftool
ovftool vi://<esx_ip>/<vm_display_name> <file.ovf> # Note: If <vm_display_name> is left off, the server will return a list of options