Domain Cloning

Once a template system has been installed, that system can be cloned. virt-clone will automatically change the MAC address of your network device.

Cloning

Use the script below to clone your template.

domain_clone.sh

   1 #!/bin/sh
   2 
   3 LVM_GROUP="vg2"
   4 NAME_ORIGINAL="stretch-template"
   5 LVM_NAME_ORIGINAL="kvm_${NAME_ORIGINAL}_vda"
   6 LVM_SIZE_ORIGINAL=`lvs /dev/${LVM_GROUP}/${LVM_NAME_ORIGINAL} -o LV_SIZE --noheadings --units B --nosuffix`
   7 NAME_CLONE="stretch-clone"
   8 LVM_NAME_CLONE="kvm_${NAME_CLONE}_vda"
   9 
  10 if [ $# -gt 0 ]
  11 then
  12         NAME_CLONE=${1}
  13         LVM_NAME_CLONE="kvm_${NAME_CLONE}_vda"
  14 fi
  15 
  16 if [ ! -e /dev/${LVM_GROUP}/${LVM_NAME_CLONE} ]
  17 then
  18         # create lvm partition
  19         lvcreate --size ${LVM_SIZE_ORIGINAL}B --name ${LVM_NAME_CLONE} ${LVM_GROUP}
  20 
  21         # clone the domain
  22         virt-clone --original ${NAME_ORIGINAL} --name ${NAME_CLONE} --file /dev/${LVM_GROUP}/${LVM_NAME_CLONE} --check path_in_use=off,path_exists=off
  23 else
  24         echo "${0}: refusing to overwrite existing domain"
  25 fi

Make a clone.

./domain_clone.sh clone

Console Access

Remove console access by editing the domain.

Memory

Increase or decrease amount of memory by editing the domain.

Unique keys for ssh

Make sure your clone does indeed have unique ssh keys. This is a really important step when cloning. Consider all your clones had the same ssh keys, that would really be a mess.

rm /etc/ssh/ssh_host_*
dpkg-reconfigure openssh-server
service sshd restart

Hostname

Change the hostname of your new guest.

cp /etc/hosts /etc/hosts.bak
sed -i "s/stretch-template/clone/g" /etc/hosts
cp /etc/hostname /etc/hostname.bak
sed -i "s/stretch-template/clone/g" /etc/hostname

Root password

Make sure to change the root password.

passwd