According to users and analysts at the Storage Decisions conference
this week, storage virtualisation products that create an
abstraction layer over the entire environment are finally beginning
to see the light of day in production.
Most notable among the technology's early adopters is Jeff
Boles, IT manager for the City of Mesa, Aris. He uses startup
Incipient Inc.'s split-path virtualisation product, the Incipient
Network Storage Platform (iNSP), which runs on a blade on the Cisco
Systems Inc. MDS director.
Debate continues in the industry about the proper place for
virtualisation, but Boles said he feels strongly that it belongs in
the switch. In fact, he said, he bought Cisco's MDS director as
well as the Storage Services Manager (SSM) blade, specifically
because of the opportunity to manage his environment from the
fabric through a product like Incipient. The MDS manages virtual
storage area networks (SAN) that separate data paths for each of
the city's 24 different departments.
The switch was the best place for storage virtualisation in his
shop, Boles said, because he wanted to have "a long-term solution
built on the parts of our infrastructure most likely to be around
the longest, which is the fabric." While the City of Mesa's arrays
are refreshed, typically once every three years, the switching
fabric is expected to last ten or more, he said.
Change also happens quickly in his environment, he said -- for
example, the city's court system has begun a document-scanning
project expected to see the addition of 20,000 document files per
day -- and the IT department typically has very little lead time to
prepare for new projects. In order to be able to add storage
quickly and at the best prices, Boles said, having a fabric-level
virtualisation product that could take snapshots, migrate data and
provision across a heterogeneous environment was ideal.
So far, the City of Mesa is using the iSNP on 150 terabytes (TB)
of Hewlett-Packard Co. (HP) EVA6000 arrays, but it is hoping to add
a 7 TB EMC Corp. Symmetrix array to the mix.
Though the management of heterogeneous storage remains an unmet
goal in his shop for the time being, Boles said he has already seen
a benefit within his HP environment. Specifically, he said, he's
content with the performance of the EVA6000, but were it not for
the ability to pool his virtualised storage, he might have to buy
the EVA8000 simply for the added capacity -- an expensive
proposition. "And I'd still be managing separate SAN islands," he
added.
Replication and disaster recovery are not problems he's been
able to solve yet using virtualisation, Boles said. For now, he'd
rather focus on improving his primary storage environment before
branching out into more services.
IBM SVC has 2,200 customers and growing
Speaking to attendees alongside Boles during a panel discussion
at the conference was IBM SAN Volume Controller (SVC) user J. Nick
Otto, IT manager for Circuit City. Otto said he dove into
virtualisation headfirst in an effort to keep spending on his
primary storage flat. Circuit City has the SVC, an in-band product
consisting of software on clustered commodity Intel Corp. servers,
in a four-node configuration in its primary datacente and a
two-node setup in its secondary datacente.
In the primary datacente, the SVC shuttles data between three
tiers of storage, all of it IBM -- a DS8100 and DS4800 array for
Tier-1, a DS4500 for Tier-2 and a DS 4100 for Tier-3. Tier-1 is
Fibre Channel (FC) disk; Tier-2 and Tier-3 use SATA disk. Because
of the 16 GB of cache on the SVC, as well as the load balancing it
performs across arrays, Tier-2 and Tier-3 performance was improved
enough to keep Tier-1 spending flat, a savings of $1 million in his
150 TB environment, Otto said.
While implementing the SVC, Otto also said Circuit City upgraded
its Brocade Communications Systems Inc. switching fabric from 1
Gbps switches to 4 Gbps models and from multiple-edge switches to
Silkworm 48000 directors. During this update, 156 TB of data were
migrated through the SVC within 60 days without a single outage,
according to Otto.
Some attendees still wary
Otto was gung ho in his presentation, but was questioned during
a Q&A period by other users, including one who said he had
investigated the SVC but hadn't liked it because it was a "black
box," and he feared cutting off his visibility into the environment
when he wanted it.
"I've bet the farm on virtualisation," Otto admitted, but added
that IBM's TotalStorage Productivity Center had also been a
necessary investment in order to get good monitoring and reporting
on his storage environment. "We did have to make a fairly
substantial investment."
Both Boles and Otto were questioned on their ability to back out
of their virtualisation products if necessary. "I wouldn't want to
do it because we'd take a huge performance hit on our lower tiers
of storage -- it would be a huge headache," Otto said. But in terms
of distribution of his data, he said ripping out the SVC, if
absolutely necessary, didn't worry him.
"Incipient's product maintains a fairly intact block-data
stream," according to Boles. He, too, said he was committed to a
virtualised environment and had not encountered any issues so far,
"but of course, you want to be cautious about making such a big
change, and be able to backtrack if it's absolutely necessary."
The big picture: Thinking outside the box … literally
Analysts at the show also said they saw virtualisation making a
stronger push in the market, though it's still only beginning.
"It's past the hype and then the low-point stage any new
technology goes through, where first there's lots of noise around
it and then some letdown," said Arun Taneja, founder and consulting
analyst with the Taneja Group."
In his keynote speech on Thursday morning, Enterprise Strategy
Group founder and analyst Steve Duplessie predicted that
ultimately, IT would rely on an entirely virtualised datacente with
an overarching operating system (OS) like that on a PC, which would
allow the allocation of storage and memory resources as necessary
without user intervention.
"You don't need to decide how much virtual memory your PC should
allocate to iTunes," Duplessie said.
Though that future is still a long way off, Duplessie urged
attendees to start soon in applying new virtualisation schemes.
"You're already using virtualisation in some form if you're using
RAID," he said. "Any move up the continuum is worth it."