Backup Strategies for Integrity Virtual Machines

Introduction
Data protection – arguably the most important aspect of data center management – applies to any
system whether it is physical, partitioned, or virtual. The architecture of HP Integrity Virtual Machines
(Integrity VM) enables multiple approaches to data protection for virtual machines, providing the
flexibility to apply existing backup and recovery solutions to your virtual environment.
This white paper outlines various strategies for backing up critical data, including both the virtual
environment definition as well as that used by applications running in virtual systems. By providing
you with the advantages and caveats of each approach here, you may choose the best solutions for
your environment.
In illustrating the various backup and recovery
(B&R) strategies, it is important to establish two
basic concepts. There are two entities (manifested
as agents, daemons, etc.) common to almost all
Enterprise Backup Solutions (EBS). We will borrow
terminology from the HP DataProtector software
product to reference these entities. First, there is
the disk agent – an entity that writes or reads data
to or from (disk) storage on a computer system and
sends or receives that data to or from a media
agent. The media agent is an entity that reads or
writes from or to media in the backup device (e.g.,
tape) and sends or receives data from the disk agent.
Basic Aspects of Data Protection for Virtual Environments
At a high level, the Integrity VM architecture consists of a VM Host system and the virtual machines –
often referred to as guests – that run on that VM Host system. Figure 1 illustrates the relationship
between these basic entities.
Virtual disks on the virtual machines map to one of three basic storage types residing on the VM Host
system:
1. Whole logical storage units, either entire disks or SAN LUNs,
2. Logical volumes, and
3. Files
This fact provides the foundation for two basic data protection paradigms for Integrity VM
environments
Graphics used to represent the disk agent (DA) and media
agent (MA) entities