The Changing Backup Target

target darts

Businesses have a variety of backup target options, plus numerous options within each target. As always when making a significant purchase, IT must first understand its data center’s needs in order to match them with vendor offerings.

Some factors are common to most enterprise backup decisions including massive data growth and near-continuous service level requirements for mission- and business-critical applications. Recovery is also a critical component: although this is perfectly obvious, not every backup product researcher pays as much attention to recovery rates as they should. Fast backup and restore performance – or the lack thereof — will affect recovery points, time objectives and the size of backup windows.

The Targets


No matter how often HDD manufacturers talk tape down, it still remains a popular. Reasons include well-established legacy equipment and processes, regulatory issues, massive data retention needs, active archiving, and controlling costs.

Tape media and tape drives are growing capacity and performance speeds at a fast clip, and tape manufacturers are pouring money into R&D. And although tape is still a popular primary backup target, it is also acting more in specialized capacities including active archiving, secondary backup from disk (D2D2T), and long-term data retention for compliance.

Outlook: Tape libraries replace tape autoloaders in order to centralize tape management. Enterprise continues to invest in libraries for compliance, long-term data retention, and active archiving with big data analysis.

Virtual Tape Libraries (VTL)

VTLs have been losing popularity and market share for some time. The reason that they were popular is when companies preferred to back up to disk but backup applications generally expected tape, and upgrades and scripting were time-consuming and expensive. VTLs filled the gap by providing the application with the appearance of tape, while actually backing up to higher performing disk for faster backup and recovery.

Outlook: VTLs are still selling but their market share is shrinking. Their best usage is legacy applications that still expect tape backup, as well as established backup processes that are still working for the business.

Backup Arrays with Deduplication

Adding new tape drives is simple. Adding spindles is not. This makes dedupe and compression critical for disk-based backup, especially given increasing sizes. Dedupe features are very common in backup software, especially products that transport data over the WAN. Dedupe may also run as a native feature in a secondary storage backup array, or a deduplication array.

The advantage of dedupe arrays is efficiently storing deduped and compressed backup on nearline disk. Logical capacity is far greater than physical capacity, especially with data that responds best to dedupe. A typical example is NAS data because of high redundancy rates (think of email threads and shared attachments). VMs also respond very well to dedupe. Applications that do not generally have high dedupe rates are collaborative products like Lotus Notes and structured databases that do not have high redundancy rates. Digital files also do not dedupe very effectively.

Outlook: Invest in dedupe arrays for those applications that benefit most from it: NAS and virtual environments. This is a particularly strong advantage given fast-growing VM farms at many businesses.

Unified Backup Appliance

Integrated backup appliances offer backup software and storage in a turnkey unit. These appliances usually offer dedupe options as well, but unlike the specialized dedupe arrays they also provide the backup software and backup storage management process. Simplicity and cost control is the watchword here, and multiple appliances that can integrate with each other will provide centralized administration and scalability.

What these appliances lack is multi-vendor flexibility, although newer products provide more integration points than previous models offered.

Outlook: Physical and virtual backup appliances are a fast-growing market. Massively growing backup data and minimal IT headcount will continue to make appliance simplicity very attractive.

Backup to the Cloud

Cloud backup is highly scalable, and managed Backup as a Service (BaaS) removes management overhead from admins. However, cloud backup and restore speeds can be magnitudes slower than over a LAN, and considerably slower even than tape. This makes cloud a good choice for cold storage, secondary backup copies for DR, and for backups that are not likely to need recovery within the first 2-4 weeks.

The two primary cloud backup approaches are in-house backup management using the cloud as a backup target, and Backup as a Service (BaaS). The former keeps control of backup and restore in-house and will save on hard costs by not leasing the backup service. However, there will be employee costs from in-house management time. BaaS manages the complexity of backing up to and restoring from the cloud, which can be considerable. The monthly costs however will grow as you add more backup data. Best practices are to contract with a service provider who has generous monthly terms.

So Which Should You Pick?

Ultimately the choice of backup targets is never black or white, and you will likely invest in several of them. A small team? You’ll want management simplicity. Look to unified backup appliances and Backup as a Service in the cloud. Prefer disk or flash to tape but backup data is growing? Look to specialized dedupe arrays and secondary storage arrays with native dedupe. Have legacy applications that expect tape? Look to tape and VTLs. Want active archiving for big data and long-term archival storage? Look to tape libraries for active and cloud-based for cold storage.

And for all backup target options consider service levels, performance, simplicity, flexibility, and robust storage services such as deduplication, security, and automated storage tiering.