Linux LVM Snapshot VM Backup Script

I thought it might be useful to someone so I'm posting the perl script I use to do daily backups of my Virtual Machines.

The script handles running machines by suspending them, taking an LVM snapshot, then resuming the VM and doing a backup of the snapshot. This gives me a window of less than 60 seconds of downtime per running virtual machine. You will need to customize this to your own LVM volume names, paths, etc.

Note: The editor seems to modify the text so I have attached the script.

#!/usr/bin/perl -w

#

1. VM Server Virtual Machine Snapshot Backups

#

use VMware::VmPerl;

use VMware::VmPerl::VM;

use VMware::VmPerl::Server;

use VMware::VmPerl::ConnectParams;

use File::Basename;

use strict;

my $backupdir = "/vm/Backups/daily";

my $log_file = "/var/log/vmware/vmbackup.log";

my ($server, $vm);

my $server_name = undef;

my $user        = undef;

my $passwd      = undef;

1. Use the default port of 902.  Change this if your port is different.

my $port = 902;

open LOG, ">>$log_file";

log_stuff( "Starting backups" );

#

1. Connect to VMware Server

#

my $connect_params = VMware::VmPerl::ConnectParams::new($server_name,$port,$user,$passwd);

$server = VMware::VmPerl::Server::new();

if (!$server->connect($connect_params)) {

my ($error_number, $error_string) = $server->get_last_error();

log_stuff( "Connect to server: $error_number: $error_string\n" );

die "Could not connect to server: Error $error_number: $error_string\n";

}

#

1. Get list of Virtual Machines

#

my @vmlist = $server->registered_vm_names();

if (!defined($vmlist[0])) {

my ($error_number, $error_string) = $server->get_last_error();

log_stuff( "get_vms: $error_number: $error_string" );

die "Could not get list of VMs from server: Error $error_number: $error_string\n";

}

#

1. Virtual Machine Backup

#

foreach my $conf (@vmlist) {

my ($name,$vmdir,$suffix) = fileparse($conf, '\..*' );

1. connect to virtual machine

$vm = VMware::VmPerl::VM::new();

if (!$vm->connect($connect_params, $conf)) {

my ($error_number, $error_string) = $vm->get_last_error();

log_stuff( "Connect to $conf: $error_number: $error_string\n" );

die "Could not connect to $conf: Error $error_number: $error_string\n";

}

1. Get the virtual machine display name

my $displayName = $vm->get_config("displayName");

$displayName =~ s/[\()]//g;  # remove special characters

1. Build the path for the backup filename

my $backup = "$backupdir/$displayName.tar.gz";

1. Get the current state for the virtual machine

my $state =  $vm->get_execution_state();

1. Log what we are doing

log_stuff( "$displayName: Starting backup" );

1. handle virtual machines that are running by using lvm snapshot with a suspend

if ( $state eq VM_EXECUTION_STATE_ON )

{

log_stuff( "$displayName: Suspending Virtual Machine" );

if (!$vm->suspend()) {

my ($error_number, $error_string) = $vm->get_last_error();

log_stuff( "suspend $conf: $error_number: $error_string\n" );

}

else

{

log_stuff( "$displayName: Creating LVM Snapshot" );

log_stuff( `lvremove -f /dev/data/vmsnapshot` );

log_stuff( `lvcreate -L9.85G -s -n vmsnapshot /dev/data/vmware` );

log_stuff( "$displayName: Resuming Virtual Machine" );

if (!$vm->start()) {

my ($error_number, $error_string) = $vm->get_last_error();

log_stuff( "start $conf: $error_number: $error_string\n" );

}

log_stuff( "$displayName: Mounting LVM Snapshot" );

log_stuff( `mount -t ext3 -v -r /dev/data/vmsnapshot /mnt` );

1. fix directory to use the snapshot instead of the actual file

$vmdir =~ s!/vm/Machines!/mnt!g;

log_stuff( "$displayName: Backup $vmdir -> $backup.tmp" );

log_stuff( `tar czpf $backup.tmp -C $vmdir .` );

log_stuff( "$displayName: Removing LVM Snapshot" );

log_stuff( `umount -v /mnt` );

log_stuff( `lvremove -f /dev/data/vmsnapshot` );

}

}

else

{

1. regular backup of suspended or offline machines

log_stuff( "$displayName: Backup $vmdir -> $backup.tmp" );

log_stuff( `tar czpf $backup.tmp -C $vmdir .` );

}

log_stuff( "$displayName: Moving $backup.tmp to $backup" );

log_stuff( `mv -vf $backup.tmp $backup` );

log_stuff( "$displayName: Backup Completed" );

$vm->disconnect();

}

#

1. Logging

#

sub log_stuff

{

my $msg = shift();

if ( $msg )

{

chomp($msg);

my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtime(time);

printf LOG "%4d-%02d-%02d %02d:%02d:%02d $msg\n", $year1900,$mon1,$mday,$hour,$min,$sec;

}

}

1. Destroys the server object, thus disconnecting from the server.

$server->disconnect();

undef $server;

log_stuff( "Completed backups" );

close LOG;