Storage virtualisation products are finally seeing the light of day
thanks to resellers finding ways to make this technology useful in
the day-to-day lives of storage administrators.
"Adoption has been slower than one would have hoped -- we
thought it was going to mirror the
Fibre Channel market, but people have moved
more cautiously," said Paul Gavazzi, director of solutions
architecture for Agilysys Inc., a reseller and integrator based
in Mayfield Heights, Ohio.
However, he says that caution is gradually giving way to action,
an opinion echoed by Datalink Corp., a reseller in Chanhassen,
Minn. According to Scott Robinson, Datalink's chief technology
officer, its newly minted storage virtualisation practice has been
up and running about six months. "Virtualisation is a word you have
to be careful about because it means different things to different
people, but that said, we're definitely seeing some increased
market interest," Robinson said. "Customers need that technology as
the next step in the evolution of a consolidated storage
infrastructure."
Of course, where businesses are on the storage learning curve has a
great deal to do with their relative interest in virtualisation.
There's a certain cycle of storage adoption, Gavaszi says, going
from
direct attached storage (DAS) to
storage area network (SAN) islands to a more
integrated SAN infrastructure. "Once you integrate those islands
of SAN, you start to think about virtualisation," he said.
Storage value added resellers (VARs) like Robinson and Gavazzi
say they are installing storage virtualisation tools for a number
of reasons, ranging from the aforementioned consolidation projects,
as well as
replication and disaster recovery. Here are
a few of the virtualisation tales that these folks can tell.
Flexibility and managementDatalink's Robinson cites one customer, a large company in the
financial services industry, that managed a large number of big
storage boxes on a SAN and wanted freedom from proprietary high-end
storage devices. The goal was to put in a
tiered storage environment that was as free
as possible from proprietary vendor environments. "They wanted
tiered storage, but they wanted to manage it simply, and they
wanted flexibility in their storage choices so that they could
hold vendors more accountable," Robinson said. It also wanted to
manage storage more efficiently by consolidating storage across
boxes, rather than within each one.
Robinson worked with the company to install Hitachi Data System
Inc.'s (HDS) Universal Storage Platform, HDS's virtualisation
architecture. The preexisting high-end storage devices are behind
the HDS universal storage platform (USP) box, as is Tier-2 storage
that the company also installed. "The HDS unit is a single point of
connection for both their Tier-1 and Tier-2 storage," according to
Robinson. "There's a single management console within USP that
manages them both."
Robinson says that the company will save money long term by better
utilising existing storage, as well as being free to choose storage
devices based on the most attractive deal, rather than being tied
to one vendor. However, he notes, "This is a big investment. USP
comes tied to a very large box." Enterprise class shops might find
it worth the price of admission, but even USP doesn't ensure
complete vendor flexibility. "The challenge is that they made a
commitment to the HDS platform, so you can't say that it frees them
completely from vendor lock in," he added.
Long-term cost control
"Most of our customers are looking for tangible benefits in
terms of cost avoidance," Gavazzi said, and storage virtualisation
offers the opportunity to bring costs down through better
utilisation of storage, as well as the ability to buy cheaper
storage for use in a tiered environment. He tells the story of a
West Coast teaching hospital that his company recently worked with
to install IBM's SAN Volume Controller (SVC) virtualisation
software. The hospital was challenged by rapid data growth that
strained its storage budget. Moreover, the all-IBM shop
traditionally bought high-end systems and used them for every type
of application, from mission critical to low end.
The SVC installation saved money on several fronts. The first
was through better utilisation of existing storage. "They had on
the order of 5 terabytes (TB) to 10 TB of storage installed and
were using about 60%, which meant that basically 4 TB was locked up
behind whatever storage in whatever array," said Adam Adatepe,
senior solutions architect at Agilysys. "Using virtualisation meant
that they could use that previously unavailable storage, which
helped them avoid the cost of an additional 4 TB of storage going
forward."
It also allowed them to implement an integrated tiered
environment, in which less vital data could be downloaded off the
high-end storage to middle- and low-end storage. The hospital now
has the DW 4800 for high end, an older IBM Shark in the midtier and
SATA disks on the low end. "We can put Fibre
Channel and SATA disks on the same storage server and the SVC
will manage it all," Gavazzi said.
More affordable disaster recovery
In the wake of last year's disastrous hurricane season, Weston,
Fla.-based Fairway Consulting Group found itself installing
virtualisation technology for a number of companies that had found
out the hard way the importance of good disaster recovery
procedures. James Price, president of the company, tells the story
of one client, who he says is the fourth or fifth largest nonprofit
charity in the U.S., with about $900 million in assets. Its primary
data center is in Miami, and the company suffered an outage after
Hurricane Wilma came through. "This was just after Katrina, and
they were in the process of releasing about $35,000 of disaster
relief funds," Price said. "Then they were hit with Wilma, and
because their own systems were down, they couldn't finish the
process."
As part of an overhaul of its disaster recovery process, the
company decided to set up a remote data center in California, but
its recent investment in a Hewlett-Packard Co. (HP) EVA storage
array had left them with minimal funds. "They wanted to double
storage, have that be highly available and wanted to be in DR
configuration with their remote data center in California,"
according to Price.
They are installing storage virtualization software from
DataCore Software Corp. in the Miami center to create a near
real-time replicated environment between the two data centers.
"They have a 100 MB dedicated circuit between the two, so even
though the centers are nearly 3,000 miles away, the latency is
really nominal," Price said. Moreover, since DataCore's software is
hardware neutral, Price will be able to build the remote site on
the cheap. "DataCore doesn't require cutting edge hardware," he
said. "We're beefing up some old chassis and combining them with
SATA enclosures and building a remote site based on that." The
Miami data center, meanwhile, has the HP server, as well a lower
end Fibre Channel-based array.
DataCore sits in front of the
storage provisioning from the array to the
storage client. It virtualises the storage and presents it back
out to the client. It also simplifies the replication process.
"When I
snapshot a virtual
[logical unit number] LUN, I'm only
snapshotting the delta of data actually written. So you don't
have to have the same amount of space available remotely -- just
the delta difference. And you can leverage low-cost storage to
provide that," Price said.