Although the role of tape in traditional backup operations might be diminishing, it still has a place in long-term data retention and even cloud storage services.
According to the Enterprise Strategy Group's Trends in Data Protection Modernization, tape is in use in 56% of data protection strategies today. That represents a lot of tape users, suggesting tape is far from dead as some have declared. If you look at archiving solutions (not to be confused with long-term retention during backup), the use of tape would be even higher. But since our focus is on data protection instead of data management, consider the following stats derived from surveying 330 users, with a 60/40 mix of enterprise and midmarket respondents.
- Data backup methods currently used:
- To disk; copy sent off-site on removable media: 31%
- To disk; no off-site copy: 15%
- To tape; copy sent off-site on removable media: 15%
- To disk; copy sent to off-site disk via WAN: 15%
- To tape; no off-site copy: 10%
- Over WAN directly to second corporate site; no on-site copy: 7%
- To disk; copy sent to cloud storage provider: 5%
- To third-party cloud storage provider; no on-site copy: 2%
Today, 25% of companies use tape as their only medium for recovery, which includes 10% backing up directly to tape, and another 15% having tapes both on- and off-site. Even compared to a collective 73% of folks who use disk as their first tier of recovery, the tape number seems high. As a first tier of recovery, I expect the tape numbers will continue to gradually shrink, with even more companies moving to disk-to-disk-to-tape (D2D2T) and using disk as their primary recovery medium, before storing data on tape for longer-term retention.
In contrast, with all the cloud storage hype we hear, only 7% of respondents use cloud in their data protection strategy, including 2% going directly to backup-as-a-service (BaaS) offerings. Another 5% back up to local disk (presumably for faster recovery scenarios, deduplication and buffering) before shipping backup data to a cloud provider through an enhanced BaaS scenario or by leveraging cloud-based storage attached to their on-premises backup application.
Not your father's tape
To be fair, with newer tape formats, tape's speed and unreliability issues have been resolved, but the bad rap against tape persists. And in some cases, the old rules have actually reversed themselves.
Twenty years ago, people wanted faster/better backups than what tape could provide at the time. But backup software didn't know how to use disk effectively, so disk vendors created virtual tape libraries (VTLs), disk systems that presented as tape.
Fast forward to today, and those who want cheaper/cooler/greener storage than their existing disk solutions may be surprised to discover that tape cartridges (LTO-6 with LTFS) can be mounted as file systems. LTFS makes tape look like disk, effectively creating virtual disk devices as the antithesis of VTLs.
The role of tape in a cloudy world
If the number of users who employ tape as their primary backup target dwindles and cloud use grows, what will be the role of tape? One of tape’s roles will be economical data retention. Even with deduplication, compression, disks that spin down and other very compelling disk-based retention and archival technologies, it's hard to economically compete with the two-or-three-cents-per-gigabyte economies that tape offers.
There are, however, two trends that could contribute to a renewed interest in tape:
1) More people understand there's a difference between archiving and long-term backups. As e-discovery scenarios and regulatory requirements continue to evolve, content-savvy archival apps are becoming more mainstream to meet those needs. Archive vendors (and their customers) seem to be of the mindset that the colder the data needs to be, the more applicable tape might be as part of the solution, often with high-performance disk or flash in front of it.
2) As cloud-based storage and backup providers continue to mature, tape tiers within their infrastructures may become more compelling. The main attraction of cloud storage services is that they can scale, and providers can offer capabilities less expensively than what subscribers could do on their own. And since the usual bottleneck between a subscriber and a provider is the Internet pipe (not the storage media), service providers may embrace tape tiers within their storage services to deliver scale while lowering their own cost models.
"Tape versus disk" is as tired an argument as "snapshots versus backups." In both cases, it shouldn't have to result in an either/or decision; rather, they should be viewed as being better when used together. The same way that you might use snapshots for faster recoveries and traditional backup for restoring previous versions, disk is the preferred deduplicating first tier as a recovery solution, while tape has a role as economical, long-term retention. Sure, there are disk-based products that can dwarf the applicability of some tape implementations, just as there are some snapshot technologies that can appear to diminish the need for traditional backups.
Whatever the case, understand how you need to protect, retain and recover your data, and then keep an open mind while considering the myriad technologies that might meet those challenge while keeping an eye on costs.
About the author
Jason Buffington is a senior analyst at Enterprise Strategy Group. He focuses primarily on data protection, as well as Windows Server infrastructure, management and virtualization. He blogs at CentralizedBackup.comand tweets as @Jbuff.