This article can also be found in the Premium Editorial Download "Storage magazine: Evaluating the benefits of IP SANs."
Download it now to read this article plus other related content.
In addition to understanding and establishing service objectives, you must understand internal service capabilities and limitations. The ability to provide effective backup services is dependent on a number of elements. (See "
How capable are your backup policies?")
The goal of analyzing your backup capabilities is to establish a set of metrics that help to define the level of services that can be delivered. Typical questions you must answer are:
- How much data can be backed up per hour?
- What's the total online capacity?
- How long does it take to duplicate tapes for off-site storage?
- What's the availability of the appropriate levels of expertise to provide these services?
In many organizations, replication capabilities are viewed as independent of backup. While replication is a different set of operational processes from backup, both are really points on the same continuum of RTO and RPO capabilities when viewed from the restorability point of view.
Can you deliver?
The next step in optimizing the backup environment is rationalizing service objectives and capabilities and developing formal service offerings. It's critical to promise only what can be delivered. If the RTO of a key application with 500GB is one hour, and you can only recover at the rate of 18GB per hour, you have a serious problem (but I'm sure you already knew that).
You have to balance what's feasible, what's desired and what it costs. This is where having a clearly understood set of metrics becomes essential. If you can't meet requirements for data recovery with current resources, then either the requirements must be modified or the resources expanded. Having the data available to present to senior management and to users is the key to negotiating realistic service level agreements.
Having the right backup policies is only one part of the much-larger issue of storage management. Everything that has been discussed about service objectives and service capabilities can be applied to other areas of storage. Developing backup policies is part of a process of shifting focus from the inward perspective of storage management to an outward view focused on the needs of the business. It's possible to be good operationally (regular backups completed on time, etc.), but bad from a business point of view (unable to restore key data in the time required). Reviewing policies is a good place to begin coming to terms with that problem.
This was first published in July 2003