DataCore’s ‘solid state SANs’ with mega-caches to make storage virtualisation performance soar

Written By: Peter Williams
Published:
Content Copyright © 2009 Bloor. All Rights Reserved.

Enterprises with
virtual environments should be intrigued by DataCore Software’s developments
for its venerable software—with upcoming SANmelody 3.0 and SANsymphony 7.0
storage virtualisation releases due for general availability around month end.
These include a massive boost to SAN-wide performance and improvements to high
availability.

A slight delay has
meant DataCore providing only a pre-announcement at CeBIT this week—but it
does seem a pretty big deal. With 30,000 instances of these two venerable
solutions now installed, there could be quite a flurry of activity within the
user base alone.

Both SANmelody and SANsymphony will
now support for 64-bit “mega-caches” providing up to one terabyte (TB) of cache
memory per node; so performance will scale linearly with each node added to the
fabric. It means that the entire SAN operation for many virtual machines can be
kept in SAN-wide caches avoiding the vast majority of disk I-O.

“This
is a solid state SAN,” James Price, vice president channel and product
marketing told me, adding that this would dwarf anything in the market. “There
will be a 600–1200% performance increase.”

He explained
that while the number one
bottleneck for virtualisation was memory (CPU cycles and pure capacity), next
came storage performance—limited by I-O to virtualised disk. So the need was to scale and
deliver I-O at native speeds or more. This boost should be worth watching!

Previously
DataCore has offered up to 20 GB of cache, which Price said had been
competitive, but, driven by
increasing virtualisation, 16–32 GB cache would be a common requirement with a
lot of customers. That’s a long way from the TB maximum so provides oodles of
expansion for those who find they need more.

Price said that
its software was engineered for virtualised environments.”Virtualisation is
native to our DNA.” Work has been proceeding apace in the past. While physical
attachment would continue to be supported, the company had found over 70% of
its revenue was coming from four leading virtualisation platforms (Citrix,
Microsoft, Parallels and VMware).

This partly
explains its new optimised
disk utilisation for Citrix XenServer, XenDesktop and XenApp environments, with
the solutions ‘Citrix Ready’ for XenServer 5. This should mean an affordable,
simple-to-run but flexible way of configuring and managing storage systems—in
combination with the scalability already described.

The
company is also offering a suite of SANmelody-based Business Continuity (BC)
and Disaster Recovery (DR) packages for Citrix environments including BC/DR SAN
Starter Virtualisation bundles, BC/DR 32 TB SAN Virtualisation bundle, as well
as SANsymphony bundles. Because of the performance boost, it becomes feasible
for Citrix customers, in particular, to grow their storage pools from a few
hundred gigabytes to multiple petabytes.

In
fact, it looks like DataCore
is thinking especially of large enterprises and cloud storage environments. It
refers to immense
storage pools which will be in constant flux—and the product enhancements have
been fully integrated into DataCore’s high availability solutions for Citrix
disk farms. DataCore is claiming maintenance, upgrades, expansion, and failures
to parts of the storage infrastructure can occur without application
disruption.

There’s
also optional ‘before- and after- the fact’ thin provisioning of virtual disks for
SANmelody and SANsymphony to avoid tying up physical capacity. Since virtual
machines typically use only a small fraction of the total volume assigned to
them, the software will automatically reclaim thinly provisioned space previously
occupied in the background after applications or file systems zero it out. So
the SAN gives back capacity temporarily needed to optimise resource usage.

DataCore’s
“Transporter” migration facility is another new option designed to cut out long
backups and restores caused by complicated format conversions. It migrates disk
images and workloads between different operating systems, hypervisors and
storage subsystems.

Finally
(for now because there is more), a re-architecting of SANmelody 3.0 and
SANsymphony 7.0 has been needed to fully exploit the power and scalability of
64-bit Windows Server 2008—both virtual and physical platforms—to provide universal
storage controllers. Everything in these solutions will now support x64
technology.

So it
all sounds good but the proof will be in the eating; only a few weeks to wait.