There are a lot of benefits with cloud computing –
cost-effective resource use, rapid provisioning, scalability and elasticity.
One of the most significant advantages to cloud computing is how it changes
disaster recovery, making it more cost-effective and lowering the bar for
enterprises to deploy comprehensive DR plans for their entire IT
infrastructure. Cloud Computing delivers faster recovery times and multi-site
availability at a fraction of the cost of conventional disaster recovery. 

What Changes in the

Cloud computing, based on virtualization, takes a very
different approach to disaster recovery. With virtualization, the entire
server, including the operating system, applications, patches and data is encapsulated
into a single software bundle or virtual server. This entire virtual server can
be copied or backed up to an offsite data center and spun up on a virtual host
in a matter of minutes. 

Since the virtual server is hardware independent, the
operating system, applications, patches and data can be safely and accurately
transferred from one data center to a second data center without the burden of
reloading each component of the server.  
This can dramatically reduce recovery times compared to conventional
(non-virtualized) disaster recovery approaches where servers need to be loaded
with the OS and application software and patched to the last configuration used
in production before the data can be restored.

The cloud shifts the disaster recovery tradeoff curve to the
left, as shown below.  With cloud computing
(as represented by the red arrow), disaster recovery becomes much more
cost-effective with significantly faster recovery times.  

Cloud Computing Disaster Recovery Tradeoffs

When introduced with the cost-effectiveness of online backup
between data centers, tape backup no longer makes sense in the cloud. The
cost-effectiveness and recovery speed of online, offsite backup makes it
difficult to justify tape backup.

The cloud makes cold site disaster recovery antiquated. With
cloud computing, warm site disaster recovery becomes a very cost-effective
option where backups of critical servers can be spun up in minutes on a shared
or private cloud host platform.

With SAN-to-SAN replication between sites, hot site DR with
very short recovery times also becomes a much more attractive, cost-effective
option. This is a capability that was rarely delivered with conventional DR
systems due to the cost and testing challenges. One of the most exciting
capabilities of disaster recovery in the cloud is the ability to deliver
multi-site availability.  SAN replication
not only provides rapid failover to the disaster recovery site, but also the
capability to return to the production site when the DR test or disaster event
is over.

One of the added benefits of disaster recovery with cloud
computing is the ability to finely tune the costs and performance for the DR
platform. Applications and servers that are deemed less critical in a disaster
can be tuned down with less resources, while assuring that the most critical
applications get  the resources they need
to keep the business running through the disaster.

The New Critical Path
in Disaster Recovery – Networking

With the sea change in IT disaster recovery delivered by cloud computing, network
replication becomes the critical path. With fast server recovery at an offsite
data center, the critical path for a disaster recovery operation is replicating
the production network at the DR site including IP address mapping, firewall
rules & VLAN configuration.

Smart data center operators are providing full disaster
recovery services that not only replicate the servers between data centers, but
also replicate the entire network configuration in a way that recovers the
network as quickly as the backed up cloud servers.

More on DR in the

I predict we’re going to hear much more about the changes in
DR strategies with the cloud over the next year as more and more enterprises
revisit their DR plan in light of the advantages of cloud hosting.