There’s a debate going on about data protection methods right now, and it centers on “disk, tape or cloud.” Of course, cloud is a delivery mechanism, not a medium, and cloud providers are using disk and near-line tape, too.
But what kinds of media and architectures are organizations really using for backup? According to ESG research, the most common approach continues to be disk-to-disk-to-tape (D2D2T). In other words, backing up from primary disk; then leveraging secondary disk for efficient deduplication and fast, granular recovery; and finally employing tertiary tape for long-term retention. Twenty-six percent of the organizations surveyed by ESG said they use this data protection method.
Another 16% go a different route: disk-to-disk-to-cloud (D2D2C). They make sure they’ll have rapid/granular recovery if needed via the secondary disk, and they send data to the cloud for tertiary retention as well.
The tradeoff between the two data protection methods is typically related to regulatory compliance — the amount of data an organization must retain for long periods will likely influence its cloud vs. tape long-term retention decisions.
Still another 17% opt for disk-to-tape-to-tape — tape for on-site recovery, with some tapes going off-site for retention and BC/DR preparedness. Interestingly, it appears the second most common method of data protection in use today (at least among the respondents surveyed) is an all-tape system.
However, the remainder of the surveyed organizations went with “all-disk” data protection methods:
- Disk to disk for fast on-premises protection but no tertiary or off-premises retention (14%)
- Disk to disk across a WAN to another disk (11%)
- Disk across a WAN to another disk, but making centralized backups of branch/remote offices back to the main data center (6%)
- Disk to tape — i.e., traditional tape backups (6%)
- Disk to cloud (4%)
A case could be made for any of these data protection methods. And that’s the point. An organization’s recovery goals, retention requirements and economic priorities all should factor into the decision.
I love cloud backups of remote office data, though, depending on the organization’s recovery needs, I can see sending the data back to headquarters instead. I also love cloud-based data protection for endpoint devices, as long as IT oversees the process. And I think the cloud is compelling to support BC/DR, where the organization not only uses the cloud for storage, but also leverages cloud-based compute to fail over if needed.
And I’m a fan of tape, especially for organizations in retention-regulated industries and those storing data for more than two years.
Still, disk ought to be the primary means of protection and recovery. That’s because it is difficult (if not impossible) to meet today’s SLAs without having a fast on-site copy to recover from.
ESG research tells a similar story:
- Seventy-three percent of organizations use disk as their first tier of recovery. That number should rise somewhat in the future.
- However, 69% of organizations use something other than disk in their overall strategy. Nearly half (49%) use tape and 20% are using the cloud in some fashion for data protection.
- Twenty-three percent of the surveyed organizations exclusively use tape, and 4% exclusively use cloud. That tape number may recede somewhat, and the cloud number may rise — but not by much.
I expect some organizations that use tape exclusively will evolve to a disk-plus-tape model for efficiency and to help them meet tight SLAs. But those same goals will likely keep pure-cloud platforms from taking over. Disk, tape and cloud data protection methods all have their place in supporting rapid recovery, reliable retention and data agility/survivability (respectively).