VMware Communities: Message List - Linux LVM Snapshot VM Backup Script

Re: Linux LVM Snapshot VM Backup Script

bcnx — Thu, 08 Oct 2009 13:59:51 GMT

Hi,

can anyone give me an indication on how much extra space you need for snapshot for a machine (in percentages that is). I guess it's related to how much the files change in that timespan, but this is really hard to predict with VMware.

Thank you,

Bart

Re: Linux LVM Snapshot VM Backup Script

Peter_vm — Sat, 19 Jul 2008 18:47:19 GMT

It all depends what you mean by "should work right". Snapshot would complete successfully. Would that snapshot be worth anything? That depends.

Re: Linux LVM Snapshot VM Backup Script

allenby — Sat, 19 Jul 2008 15:54:23 GMT

so I can ignore the "suspending" part of that scrip and it still should work right

Re: Linux LVM Snapshot VM Backup Script

Peter_vm — Sat, 19 Jul 2008 00:27:18 GMT

Yes.

It also possible to power-off VM without running shutdown.

Re: Linux LVM Snapshot VM Backup Script

allenby — Fri, 18 Jul 2008 21:16:16 GMT

is it possible to do the snapshot with out suspending the vm?

Re: Linux LVM Snapshot VM Backup Script

postonra — Wed, 04 Jun 2008 21:34:42 GMT

Is this a script tied to VM Server or is this a tool that could be used with ESX ? Where are the LVM snapshots being created inside the VMs or on VM Server or ESX ?

Re: Linux LVM Snapshot VM Backup Script

gordho — Tue, 01 Apr 2008 14:59:29 GMT

You should be able to backup the files to any location by either modifying the my $backupdir = "/vm/Backups/daily"; variable or by mounting an nfs or cifs share to /vm/Backups/daily.

Re: Linux LVM Snapshot VM Backup Script

arman68 — Thu, 13 Mar 2008 14:46:53 GMT

Thanks for your script. I have been meaning to do something like this for a while now, but never came round to it. Could you please give us some more details on what it does? I have had a quick look at the script and this is what I understand (correct me if I am wrong):

the local server name, username and password need to be filled in
it automatically enumerates all the vm
vm which are running are first suspended (via vmware), a lvm snapshot is taken, and then the vm is resumed via vmware
the backup uses the vmware files directly, or from the lvm snapshot (when needed)
backups with tar+gzip goes to a local file
lvm snapshots are deleted once the backup is completed

A few comments/requests:

using lzop compression instead of gzip would put much less stress on the server by compressing faster (~80%) and with only ~10% extra space required; an option to choose between lzop and gzip would be useful

can the backups go somewhere else than the local server, and if so, how?

an exclude list of vm would be useful

same for the possibilty to run the script to backup only 1 specific vm

Linux LVM Snapshot VM Backup Script

bradsjm — Thu, 13 Mar 2008 00:11:21 GMT

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
#

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;

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

my $port = 902;

open LOG, ">>$log_file";
log_stuff( "Starting backups" );

#

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";
}

#

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";
}

#

Virtual Machine Backup

#
foreach my $conf (@vmlist) {
my ($name,$vmdir,$suffix) = fileparse($conf, '\..*' );

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";
}

Get the virtual machine display name

my $displayName = $vm->get_config("displayName");
$displayName =~ s/\()//g; # remove special characters

Build the path for the backup filename

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

Get the current state for the virtual machine

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

Log what we are doing

log_stuff( "$displayName: Starting backup" );

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` );

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
{

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();
}

#

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", $year+1900,$mon+1,$mday,$hour,$min,$sec;
}
}

Destroys the server object, thus disconnecting from the server.

$server->disconnect();
undef $server;

log_stuff( "Completed backups" );
close LOG;