gistfile1.txt

#!/usr/bin/ruby

$threshold = 60
$external_snapshots = "/media/external/snapshots"
$system_snapshots = "/backup/backintime/AKSCOU01.local/root/1"

# ensure correct drive is mounted

# enforce the threshold
freespace = `df -l|grep /media/external|tr -s ' ' ' '|cut -d' ' -f4`.chomp.to_i
freespace = freespace / 1024 / 1024

if freespace < $threshold
  # email us
  puts "omg no space left!"
end

# get the latest external snapshot
latest_external = Dir.entries( $external_snapshots ).sort_by{|name| 
  File.stat("#{$external_snapshots}/#{name}").mtime
}.delete_if {|n| n == "." || n == ".." }.last

# get the latest system snapshot
latest_system = Dir.entries( $system_snapshots ).sort_by{|name| 
  File.stat("#{$system_snapshots}/#{name}").mtime
}.delete_if {|n| n == "." || n == ".." }.last

# copy the snapshot folder excluding the files subdir from system to external
Dir.mkdir "#{$external_snapshots}/#{latest_system}"
system "cp #{$system_snapshots}/#{latest_system}/* #{$external_snapshots}/#{latest_system}"

# copy the files from the previous snapshot to the files subdir in the latest snapshot
system "cp -lRf #{$external_snapshots}/#{latest_external}/backup #{$external_snapshots}/#{latest_system}"

# rsync the latest files from the system files subdir to the latest external files subdir
system "rsync -a #{$system_snapshots}/#{latest_system}/backup #{$external_snapshots}/#{latest_system}"