In tiered data storage, priority data should be stored in high-performance data storage systems. As the data value...
in that storage system declines or depreciates over time, it should be moved it or migrated to lower performance and lower cost storage. Migrating the data will better align its value with the cost of storing it. Also, the concept of tiered data storage makes perfect sense and most data storage administrators attempt to tier some or all of their data.
If all data were treated in the same fashion in a company's storage environment, this would mean that the mission-critical data such as online transaction processing (OLTP), email, the organization's accounting, customer resource management (CRM) and even the server images themselves would have the same backup frequency and recoverability as marketing's press releases, PowerPoint presentations, JPEGs, Word documents, or MP3s. The real problem with treating all data the same during data backup and recovery is that it either increases the risk of losing critical data, raises the total cost of data backup and recovery, or lengthens the time needed to do regular backups. All cases ignore the fact that data backup is a means to an end with the end being data recovery from a failure caused by natural or human disasters.
In one example, all data is commonly backed up once a day, put on tape, then shipped offsite. This methodology means that the RPO is 24 hours, and the RTO is a few days or longer. This is not a good idea for an organization's mission-critical data. First, the process in recovering the data takes much too long, bringing all of the correct tapes back from offsite, and then recovering them in order, (which is subject to common human error). This can be incredibly tiresome and annoying if all that is being recovered is a single file caused by an accidental deletion. Second, it assumes all data on all tapes are recoverable. In the end, both introduce unacceptable risks to mission-critical data.
On the other hand, if all data is backed up to disk, virtual tape (disk that appears like tape) or deduplicated disk, the RTO speeds up, but raises the total cost of data backup and recovery. Unfortunately, those costs will continue to increase as the amount of data continues to grow. It makes no sense to provide higher cost rapid recovery technologies for nonessential data.
Tiered backup and recovery recommendationsdisaster recovery (DR) SATA disks
About the author: Marc Staimer is the founder, senior analyst, and CDS of Dragon Slayer Consulting in Beaverton, OR. The consulting practice of 11-plus years has focused in the areas of strategic planning, product development, and market development. With over 28 years of marketing, sales and business experience in infrastructure, storage, server, software, and virtualization, he's considered one of the industry's leading experts. Marc can be reached at firstname.lastname@example.org.