This article can also be found in the Premium Editorial Download "Storage magazine: Mobile cloud storage best practices."
Download it now to read this article plus other related content.
Agents vs. agentless
There has been some debate about the use of agents: Should the backup intelligence reside in the virtual server OS, the host or on a separate piece of hardware? While conventional wisdom states the agentless approach is better when no software is required in the guest OS, this may not actually be the case. If an agent is written correctly,
Also, even agentless products may still need to deploy an agent to get application-specific information. For example, granular backup of Exchange, SQL Server and SharePoint usually requires an agent.
Two key issues are still weaknesses for most virtual server backup products. The first, as mentioned earlier, is tape support. While the use of tape has diminished in many data centers, it’s often an integral part of backup operations at many companies. With the availability of high-capacity, high-performance media, many companies are actually looking to expand the role of tape in their environment. From a virtual server backup perspective, it’s an ideal way to store older backups for a longer period of time. Being able to selectively push to tape a series of snapshots you want to keep but won’t need instantly would free up capacity on the disk appliance and put older data on a medium designed to sit on a shelf for years.
The second issue is reporting. Advanced reporting needs to be developed to identify which virtual servers haven’t been protected in a given period of time or aren’t protected at all. In addition, effective reporting could provide information about resources consumed during the backup process so better load balancing could be arranged.
The state of virtual server backup is improving rapidly and there are many options available from a variety of vendors. The functionality gaps among those vendors are closing rapidly as well. Many of the features described here have become standard fare in most VM backup apps, but your environment -- the way it’s currently configured and its anticipated growth -- will determine which ones are required and which would be nice to have.
BIO: George Crump is president of Storage Switzerland, an IT analyst firm focused on storage and virtualization.
This was first published in September 2012