transfer_img_to_lvm.rb

#!/usr/bin/env ruby
#
# == History
# Transfers multiple *.img files from one machine to corresponding
# LVM volumes on other machine.
#
# == Requirements
# 1) This script
# 2) Passwords-less sudo on destination machine
# 3) Sudo rights on source machine
# 4) Pubkey SSH authentication from source to destination machine
# 5) Installed "pv" - shows transfer progress
#
# == Configuration
# List all images you want to transfer
PARTITIONS = [ 'web03' ]
# Source directory vith images
SRC_DIR = '/var/lib/libvirt/images'
# Destination LVM2 volume group
DST_VG = '/dev/vg0'
# How do you connect via SSH from source to destination machine?
REMOTE = 'snap@192.168.1.123'

def runme(cmd)
  puts cmd
  start = Time.now
  ret = `#{cmd}`
  diff = Time.now - start
  puts "Command took: #{diff}s\n"
  return ret
end

PARTITIONS.each do |orig_name|
  src      = "#{SRC_DIR}/#{orig_name}.img"
  dst      = "#{DST_VG}/#{orig_name}"

  puts ">>> get size of partition"
  size = (runme("du #{src}").strip.to_f / 1000000).ceil

  puts ">>> delete possible old remote partition"
  runme("ssh #{REMOTE} 'sudo /sbin/lvremove -f #{dst}'")

  puts ">>> create partition on remote end"
  runme("ssh #{REMOTE} 'sudo /sbin/lvcreate -L#{size}G -n #{orig_name} #{DST_VG}'")

  puts ">>> transfer data"
  runme("dd if=#{src} bs=4096 | pv | gzip | ssh #{REMOTE} 'gzip -d | sudo dd of=#{dst}' bs=4096")
end