Quick tutorial for evaluating backup products

This buying guide looks at the key factors involved in evaluating and selecting backup products.

The process of evaluating and purchasing data backup products can be an intimidating one. It's not enough to simply buy a new tape drive or upgrade to a larger disk -- not with data volumes growing at 60% per year.

In addition, as more vendors deliver more backup products to meet specific backup needs, it gets harder for IT organizations to make informed product choices. This backup product buying guide lists the criteria involved in selecting backup products for each backup product category and offers product specifications that will help you compare products. The notion of "data protection" has opened the door for specialized backup tools such as continuous data protection (CDP), remote replication and snapshots. Even once the backup platform is decided, you'll still need software to execute the necessary backups.

Aside from the obvious issues of pricing and support, you'll need to consider these other backup issues:

Backup windows and other recovery deadlines. You'll need to identify the backup window, recovery point objective (RPO) and recovery time objective (RTO) for your organization. A backup window is the amount of time needed to back up necessary data to disk or tape. If you only have four hours to back up 2 TB of data, you'll need a backup product that can accommodate those data transfer rates.

Many organizations perceive RPO as the amount of data they can afford to lose in the event of an incident, and RTO as the amount of time they can afford to be out of business (awaiting successful recovery). Shorter backup windows and smaller RTO/RPO objectives generally usually mean more costly backup products. The problem is that data volumes are increasing while organizations are seeking higher availability (heading toward 24/7 operation), and this is putting enormous pressure on traditional backup schemes.

The overall data protection scheme. There is no such thing as a universal backup process or product. Enterprise data typically receives several layers of protection that may include RAID, disk-to-disk (D2D), remote replication, archival storage and tape or virtual tape library (VTL) systems. For example, data on a Fibre Channel (FC) disk array may initially be protected through RAID-5, then replicated to a remote SATA disk array implementing RAID-6/DP and finally be backed up to tape periodically. You should determine the role that the new backup product will play in the overall data protection scheme.

Hardware and software interoperability New backup hardware that requires major redesigns or workarounds in the data center will be a major headache for everyone. For example, a backup system with Gigabit Ethernet connectivity would probably be a poor choice for deployment on a 4 Gbps FC SAN. A backup product should fit within your existing hardware/software infrastructure; it should integrate smoothly with an existing SAN or LAN and be recognized by popular backup tools such as EMC Corp.'s NetWorker or Symantec Corp.'s Veritas NetBackup. Ideally, new equipment should also interoperate with current tools to minimize the proliferation of new software management tools in the enterprise.

The recovery process. Even the best backup process is useless if the data cannot be restored. That's why so many organizations are paying attention to the recovery and restoration aspects of backup products. You should know what's involved in restoration and who can initiate the process. For example, a full tape restoration may require the intervention of an experienced backup administrator, while a continuous data protection (CDP) or content-addressed storage (CAS) system may allow users to recover individual files on demand without IT intervention. Recovery processes should be routinely tested and refined to ensure that all necessary storage systems are protected and that personnel will be able to execute the recovery if the need arises.

Scalability of the backup product. You should understand how the backup product will scale as enterprise demands change. Capacity should be scalable through the addition of more disk or tape drives. Throughput should also scale through better network connectivity or other techniques such as clustering. For example, Qualstar Corp.'s TLS-8000 Series enterprise-class tape library can support up to eight LTO Ultrium tape drives and store up to 264 tapes in the cabinet. In contrast, the Lightning 9980V storage system from Hitachi Data Systems (HDS) scales to 140 TB with up to 1024 drives (which includes spare drives).

Security. Backups often contain sensitive information such as client details or internal records, so any backup product should include security features that protect data against loss or theft. For disk-based backup systems such as CAS, CDP or VTL, security may include user authentication, which ensures that only authorized users can access and restore data.

Many tape-based backup systems include encryption. For example, the PX720 from Quantum Corp. currently includes DataFort encryption appliances from Decru, and the T950 library from SpectraLogic Corp. uses the encryption features of its BlueScale software. LTO-4 tape drive technology includes encryption capability in the drive itself.


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