VMware offers a backup system for virtual machines: VCB (VMware consolidated Backup): http://www.vmware.com/products/vi/cb_overview.htm
When the VCB run it:
- execute a snapshot of VM
- clone virtual machine disks
- consolidates the snapshot (snapshot removing)
The advantages of this backup system are:
- full backup of a virtual machine
- no downtime
- the filesystem should be consistent
The disadvantages are:
- full backup of a virtual machine (read: no incremental or differential)
- is snapshot dependent (no RDM or indipendent devices)
Basically VCB is a good sistem for disaster recovery (whether the restrictions imposed by the use of snapshots ad not too restrictive).
With a lot of bash line is possible to implement a similar system by automating the snapshot, cloning and consolitation operations.
Lo script in questione è pmvcb: pmvcb esegue le operazioni sopra elencate su un host ESXi. This is the goal of pvcb script.
Below the help of pvcb:
Usage: ./pmvcb -v [VM] -d [DIR] -h [host] <options>
options:
-v <vm> Virtual machine to backup [*]
-d <dir> Remote directory to store backup [*]
-h <host> ESXi host [*]
-u <user> ESXi username (default: root)
-f <opts> vmkfstool optons (default: "-a lsilogic -d zeroedthick")
-o overwrite existent backups
-q use quiesce snapshot
-s <opts> ssh options (default: "-i /var/lib/bacula/.ssh/id_rsa")
-L <cmd> local command executed after backup of virtual disks, this command is executed on local machine
-R <cmd> remote command executed on ESXi host after local command execution
-t <timeout> snapshot creation timeout in minutes. (default 10)
-U use the snapshot_id syntax in snapshot.remove (default NO)
[*] required options
The required options are: the name of VM to do backing-up (-v), the directory where pvcb store the cloned disks (-d) and the ESXi host (-h). With -f option you can specify more options to vmkfstools command (the comamnd used by ESXi for cloning disks), with -q option you can use quiescent snapshot. With -s option you can specify more options for ssh (for example using a RSA key). -L and -R run commands on localhost and remote ESXi host. -t defines the timeout for snapshot creation. -U supports the snapshot_id in snapshot.remove.
pmvcb deals with:
- verify that the virtual machine not have RDM or indipendent disks
- verify that there are not snapshot in progress
- executing the snapshot
- disk cloning and copy .vmx file of virtual machine in the direcotry specified by -d option
- consolidate the snapshot
- executing command specified by -L option locally
- executing command specified by -R option remotely
really recommended to use rsa authentication with ssh (http://plone.lucidsolutions.co.nz/linux/vmware/esxi/enabling-ssh-with-public-key-authentication-on-vmware-esxi-4)
this script is tested on ESXi 4.0 / 4.1
