First there was 9-11. Then four hurricanes in succession hit
Florida late last summer. And finally, a massive tsunami swept Asia
in late December. Hidden among the many lessons that this series of
manmade and natural disasters taught is a vital message for storage
administrators: The recovery copy of your data had better be stored
offsite--far offsite.
Although small companies might archive data offsite, typically
they have the backup copy of their data running right next to the
production copy, if they have an up-to-date backup copy at all. They
imagine that the need for recovery will be driven by a system
failure or human error, not a major disaster. Larger companies often
store their company backup data off site but nearby. "Before 9-11,
companies would move their data 20 minutes away," says Robert
MacIntyre, vice president of marketing and business development for
NetEx, a provider of data-transport optimization technology. "Now
they need to store it out of the region of mass destruction."
Unfortunately, according to an independent study funded by NetEx,
existing WANs aren't sufficient to meet the requirements associated
with business continuity and disaster recovery applications. In a
survey of 170 IT administrators from a broad array of companies of
various sizes, 65 percent say that they believe their WAN throughput
is inadequate for business continuity/disaster recovery operations.
The survey participants have a wide variety of storage solutions in
place, including Network Attached Storage (NAS), arrays, servers,
appliances, and intelligent switched arrays. The backup method they
most frequently use is a straightforward backup to tape or disk.
However, sizeable percentages of the surveyed administrators use
more sophisticated approaches, such as point-in-time snapshots,
mirroring, and data-replication technologies.
According to the survey, the lack of adequate WAN bandwidth poses
several different challenges. Perhaps the most important is its
effect on daily operations. As data volumes grow, administrators
find it increasingly difficult to perform backup operations within
the available timeframe. The time pressure, in turn, can lead to an
even more serious problem. As policies are set to prioritize backup
operations so that they can be conducted in a timely fashion,
companies might discover that not all the necessary data is, in
fact, being backed up.
And there are more challenges. As the storage infrastructure
becomes more dispersed, it becomes harder for IT administrators
simply to keep track of where data is. In fact, the need to store
data hundreds of miles away for business continuity/disaster
recovery might require adding more tiers of storage.
These administrators' concerns aren't misplaced. According to the
survey, the network bandwidth associated with their disaster
recovery applications is 10 Mbps or less, which isn't very robust
for what can be an extremely data-intensive operation.
Unfortunately, 62 percent of the respondents say that simply
increasing the network bandwidth won't solve their problems.
Indeed, providing adequate throughput for business
continuity/disaster recovery applications is a tricky problem that
probably can't be resolved in one stroke. Complicating the issue, 78
percent of the surveyed administrators indicate that they'd prefer
that their business continuity/disaster recovery application
piggyback on top of their regular TCP/IP network, and 71 percent say
that their preferred transport protocol is Ethernet/IP as opposed to
Fibre Channel/IP. In other words, administrators would prefer that
business continuity/disaster recovery simply be one more application
running on their standard network.
But business continuity/disaster recovery is very data intensive
for specific periods of time. Building an entire network to meet
that peak usage can be costly. However, if the network isn't
constructed with peak usage in mind, when backup for business
continuity/disaster recovery occurs, it could impair the service
levels for other applications.
Several companies are offering different ways to resolve the
bandwidth problem. For example, NetEx, which was spun off from
Storage Technology in 1999, and Riverbed Technology offer bandwidth-
acceleration appliances. Other companies such as Expand Networks and
Peribit Networks use data-compression technologies to increase WAN
bandwidth.
Interestingly, though, finding a technological fix is only part
of the answer. The need to store data far offsite for business
continuity/disaster recovery applications means that network
administrators and storage administrators must work more closely to
determine how to meet the requirement in a cost-effective manner
without affecting other applications. Communication is as an
important part of the solution as technology.
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