ESG Brief
Plan for Hybrid Data Protection Media
Date: January 2016 Author: Jason Buffington, Senior Analyst
Abstract: Primary and secondary storage requirements are growing at around 40% year over year, which can make a
“disk-only” protection strategy economically unfeasible these days. For that reason, just as you should plan for a
hybrid approach to data protection that includes backup, archiving, snapshots, and replication—you should also plan
for a hybrid data protection media strategy.
Introduction
Many folks talk about modern data protection in terms of complementing backups with snapshots, replication, etc.—
and there is good reason to (see Figure 1). But even just within “backup,” which is still the essential core of most data
protection strategies, it is vitally important to consider where data should be stored for protection or preservation
purposes.
Figure 1. The Spectrum of Data Protection
Source: Enterprise Strategy Group, 2016.
Disk First
For several reasons, there aren’t too many scenarios where the best place for most secondary or “protection” storage
isn’t disk. That’s because:

For most data protection (backup and archive) software solutions, the best experience is to rely on secondary
disk for ongoing backups, replication, or other data “ingest”/storage behaviors.

Even more importantly, with most IT organizations operating under downtime SLAs of just a few hours or less, it
is hard to satisfy RTO/RPO requirements without on-premises disk. Other storage media will often fall short
without local disk as a first tier of recovery.
Said another way, if it really is about data restoration, not backup, then disk is where a data management strategy
should start. ESG’s 2015 data protection modernization research shows that today, nearly three out of four IT
organizations are using disk as their first tier of recovery (see Figure 2), in large part for the reasons mentioned above. 1
ESG expects that number to continue to rise.
1
Source: ESG Research Report, 2015 Trends in Data Protection Modernization, September 2015.
© 2016 by The Enterprise Strategy Group, Inc. All Rights Reserved.
2
ESG Research Brief: Plan for Hybrid Data Protection Media
Figure 2. How Organizations Generally Manage the Data Backup Process
Thinking about your organization’s environment today, which of the following best describes how
the data backup process is generally managed? (Percent of respondents, N=375)
Data is initially backed up to onsite disk storage and a copy is sent
off site via removable media (i.e., tape) (D2D2T)
26%
Data is initially backed up to onsite tape storage and a copy is sent
off site via removable media (i.e., tape) (D2T2T)
17%
Data is initially backed up to onsite disk storage and a copy is then
sent to a cloud storage service provider (D2D2C)
16%
Data is backed up to onsite disk storage with no offsite copy (D2D)
14%
Data is initially backed up to onsite disk storage and a copy is sent
over the WAN to offsite disk (D2D2WAN)
12%
Data is backed up over the WAN directly to a secondary corporate
site such as a headquarters location or other corporate data
center (no onsite storage of backup data) (D2WAN)
6%
Data is backed up to onsite tape storage with no offsite copy
(D2T)
6%
Data is backed up over the WAN to a cloud service provider (no
onsite storage of backup data) (D2C)
4%
0%
5%
10%
15%
20%
25%
30%
Source: Enterprise Strategy Group, 2016.
In considering the status quo for backup media topologies (see Figure 2), it’s interesting to note that: 2

Disk is the first tier of recovery in 73% of environments today, but only 31% of environments are disk-only.

Tape is still part of nearly half (49%) of primary backup solutions today, with 23% of environments claiming to
use tape exclusively (without disk or cloud).

Cloud services* are used in 20% of primary backup scenarios today, though only 4% protect their data directly to
a cloud service.
* For accuracy, it is important to note that “cloud” is not technically a storage medium. Cloud is used in this
context to describe a cloud-based storage service, which in fact would be using its own disks, tapes, or a
combination of both to store data, albeit with a different CapEx/OpEx consumption model and value
characteristics.
That being said, more than half (52%) of the surveyed environments are using a hybrid approach to protection by first
protecting data to disk for fast recovery, and then protecting it to tertiary media including tape, cloud, or offsite disk for
longer-term retention and BC/DR preparedness. It’s a smart approach.
2
ibid.
© 2016 by The Enterprise Strategy Group, Inc. All Rights Reserved.
ESG Research Brief: Plan for Hybrid Data Protection Media
3
That’s the good news. The bad news is that primary and secondary storage requirements are growing at around 40%
year over year. IT organizations are creating 10.7 copies of data on average, thanks to all those daily/weekly/monthly
backups, BC/DR replicas, snapshots, test/dev copies, and so on. 3
So, while disk is ideal as a first tier of recovery, it is almost unfeasible economically unless you employ deduplication as
well. More than half of the IT environments ESG surveyed are using deduplicated disk arrays as part of their
infrastructure, and ESG expects that number to continue to rise, as well.4
After Protecting to Disk First, Then What?
After you have your primary production storage backed up, archived, and/or replicated to disk-based secondary
protection storage, you have options available to you:
Option: Replicate to Another Disk
Many organizations do this today. For example, it makes a lot of sense for a business with remote offices to first protect
data locally for fast recovery, then protect it to corporate headquarters for BC/DR or long-term retention.
A big benefit of “disk-to-disk-to-disk” (D2D2D or D2D2WAN in Figure 2) data protection is that the replication between
secondary and tertiary disk often happens between arrays, preserving whatever compression, deduplication, or other
optimization might have been achieved on the secondary array. In fact, a D2D2D scenario is often achieved by utilizing
virtualized deduplication appliances at the remote sites and a much larger physical deduplication target at the central
corporate facility.
Option: Replicate to Another Disk (in the Cloud)
The benefits of a virtualized dedupe array at a branch replicating data to a central IT facility also translate nicely to
service providers offering a similar service to subscription clients. This is one “D2D2C” approach: primary disk, to
secondary disk, to cloud.
For this approach, the managed service provider (MSP) can provide virtualized deduplication appliances to smaller
subscription clients to help them optimize their onsite backup solution, and then help them replicate data from that
virtual dedupe appliance to the MSP’s centralized physical target. An MSP might also provision a virtual appliance per
subscriber within its cloud facility to provide an entirely secure remote target per subscriber.
Option: Replicate to the Cloud
Today, 16% (nearly one in six) environments replicate data to the cloud—it’s a way of combining fast onsite recovery
with economical offsite data survivability in a cloud-based service.5 As mentioned earlier, one way to achieve D2D2C is
by replicating between arrays.
But some organizations use different onramps to the cloud for the tertiary copy; for instance, they may utilize the cloudconnector features within their backup software to access the block/object storage of Amazon or Azure, and then
manage the tiers (on-prem disk/off-prem cloud) within the software. Still others may use a cloud-gateway solution,
whereby something that looks like “disk” to the backup software is actually a cache to cloud storage.
All the methods provide D2D2C, with various tradeoffs and benefits. But much more interesting than backing up to the
cloud is failover within the cloud. Or, to say it another way, “Why BaaS when you can DRaaS?” Instead of simply using
the cloud as a storage tier whose data must be restored back to where it came from, why not use the compute pool in
the cloud to remount the data and resume functionality? This approach is gaining momentum every day as new vendors
and solutions continue to tackle the networking, compute, workflow, and orchestration challenges related to gaining
recovery agility from cloud-based data protection solutions.
3
ibid.
Source: ESG Research Report, The Shift Toward Data Protection Appliances, March 2015.
5 Source: ESG Research Report, 2015 Trends in Data Protection Modernization, September 2015.
4
© 2016 by The Enterprise Strategy Group, Inc. All Rights Reserved.
ESG Research Brief: Plan for Hybrid Data Protection Media
4
Option: Retain on Tape
For several good reasons, tape is still in use in nearly half of all IT environments surveyed by ESG. Most obviously, it is
nearly impossible to find an economic model for storing data for long periods in which the total cost of ownership
doesn’t favor tape as a superior medium (for regulatory compliance, information governance, or any other five-year-plus
retention requirement).
Sometimes, data must be held for non-regulatory purposes for two to five years and could exist just as safely in the
cloud as on tape. But for truly long-term retention, it’s hard to knock modern tape. And if modern is the key word in that
statement, then Linear Tape Open (LTO) technology is likely the punchline.
Thanks to a consistent outer cartridge format and ever-evolving inner-tape technology (LTO-7 was recently released),
coupled with increasing speed and a mean time between failure (MTBF) rating better than some HDD spindles, LTO is
definitely not “your father’s tape cartridge.” Add in capabilities such as the Linear Tape File System (LTFS) standard,
which truly blows the doors off any perception that tape is “only for backup/archive,” and it shouldn’t surprise anyone
that IT pros who deal with storage as a strategic part of their IT delivery are including tape as part of that strategy, with
many rediscovering the functional and economic benefits of tape along the way.
The Bigger Truth
Just as you should plan for a hybrid approach to data protection that includes backup, archiving, snapshots, and
replication, you should also plan for a hybrid data protection media strategy.
Absolutely start with deduplicated disk, but also expect to use tertiary disk, cloud(s), and tape—because to achieve the
kind of agility that your organization demands within the budgetary limits that your IT team works under, you may need
each of the three storage media to help you get where you need to go.
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© 2016 by The Enterprise Strategy Group, Inc. All Rights Reserved.