Recent IP storage growth has been impressive. According to IDC,
there were 32,124
terabytes (TB) of
iSCSI storage deployed worldwide in 2005.
That figure had almost tripled to 97,506 TB by 2006. Users are
quickly adopting IP storage for its low complexity and
deployment costs. Some organizations are using IP storage as an
alternative to scattered storage technologies that often
proliferate and cause management headaches such as NAS and DAS.
The ubiquitous nature of IP networking also positions IP storage
(a.k.a. iSCSI) networks as an ideal medium for remote backup and
disaster recovery tasks.
IDC expects almost 4 million TB of iSCSI storage to be deployed
by 2010. "We continue to believe that IP-based storage will be a
significant area of focus for vendors in 2007," says Brad Nisbet,
program manager for storage systems at IDC. But IP storage adoption
has been far more than just a numbers game. ISCSI has been making
real inroads in both small companies and large enterprises.
Positioning for low costs and rapid expansion
@31940 TransNational Communications International Inc. (TNCI) in
Boston is a reseller of voice, data and network services. TNCI
faced the problem of storage growth and limited functionality. "We
had an MSA1000 from HP," says Mike DiBenedetto, network
administrator at TNCI. "It performed well but we didn't really have
any solid management capabilities or software capabilities, like
snapshots and replication, or the ability to dynamically grow and
reprovision the storage as we wanted." With about 1.5 TB of Fibre
Channel storage in the MSA1000, TNCI eventually added two low-end
NAS systems, bringing another 1.5 TB of basic ATA storage into the
business.
The move to IP storage was not immediate. TNCI wanted more
flexibility and expansion capacity in the storage hardware, but the
costs of Fibre Channel components and switching needed to connect
numerous servers to the storage area network (SAN) made Fibre
Channel expansion prohibitive. "With Fibre, we found the average
cost of connectivity to be about $2,000 [per server] just thinking
about Fibre HBAs in those servers," DiBenedetto says, noting that
the same server can be connected to an IP SAN for around $750.
"Cost for connectivity was a major factor in choosing IP
storage."
It took TNCI almost a year to decide on iSCSI, which included a
great deal of research and hands-on testing. One pivotal factor in
its choice of iSCSI involved its important VMware Inc. ESX server
-- only recently upgraded to support iSCSI. TNCI finally settled on
two EqualLogic Inc. IP SAN arrays; the PS300 with 7 TB (about 5 TB
configured) and the PS100E with 3.5 TB (about 2.25 TB configured).
DiBenedetto points out that the EqualLogic iSCSI arrays can scale
very easily, pushing well beyond the 8 TB limit of the MSA1000.
Today, iSCSI handles the entire production environment for TNCI,
including Exchange, SQL databases and user data. "Anything
production based is running off that iSCSI SAN," he says. The older
storage systems have been relegated to storage archiving and test
purposes.
There have been significant savings in the eight months since
the introduction of IP storage. "In that timeframe, we've probably
saved $15,000 just in connectivity costs," DiBenedetto says.
Savings of 25% to 30% are also expected in ongoing storage costs as
the iSCSI storage systems are scaled up into the future. Savings
are enhanced even further with better storage utilization, which
DiBenedetto expects to approach 100%. Still, the adoption of IP
storage has its issues. DiBenedetto recommends that you certify
your critical applications for iSCSI before moving them to IP
storage and take the steps to segment and secure the IP storage
traffic to avoid bottlenecks in the production IP network.
Interestingly, the performance of IP storage seemed at least as
good as Fibre Channel -- a point that DiBenedetto attributes to
disk utilization. "They're spreading the volumes across larger
numbers of disks -- more spindles," he says. "They're using lots of
SATA or SAS disks to increase performance."
Positioning for backup and disaster recovery
A steel manufacturing giant might seem like an unlikely place
for IP SANs, but Mittal Steel USA was struggling to protect 10 TB
in DAS. Not only had backup and disaster recovery tasks emerged as
serious concerns, but Mittal also needed to centralize its storage,
improve storage management and ease upgrade disruptions, and find a
means to support storage-hungry tasks, including disk-to-disk
backups, SQL databases and Microsoft Exchange.
SAN adoption was inevitable, but the choice between Fibre
Channel and IP storage demanded a careful consideration of Mittal's
budget, technology, IT skill set, ease-of-use, expandability and
detailed discussions with other users of both technologies. During
an email interview, W. Dean Sheets, IT demand manager at Mittal,
said IP SAN technology met all of the organization's objectives --
and actually resulted in multiple iSCSI SAN deployments. "We
deployed the [iSCSI] SANs at three locations; one at the primary
U.S. data center, one at the local area disaster recovery location
and the other at a wide area DR location." The main U.S. data
center now handles 32 TB using eight arrays in a RAID-50
configuration and one array set up for RAID-10. A local disaster
recovery facility supports almost 10 TB with two arrays in a RAID-5
configuration. The U.S. disaster recovery data center handles 11 TB
with two RAID-50 arrays and one RAID-10 array.
Although Sheets declined to specify Mittal's iSCSI products, he
was clear that the move to IP storage SANs fully addressed Mittal's
performance needs. "[We] met our need for wide area SAN replication
within our WAN speed constraints," he says. "[This let us] fulfill
our plan for disk-to-disk-to-tape (D2D2T) backup -- hundreds of
servers do their backups to the SANs, which are eventually put on
tape. This allowed us to stay within backup time windows." Sheets
also pointed to the ease of Web-based management, simplified
hardware and potential to implement virtualization at some point in
the future.
Sheets notes that practical issues, like optimum NIC selection,
switch port configurations and the choice of RAID levels
(particularly RAID-10) surfaced during the deployment process.
Still, he reports that its IP SAN deployment went smoothly overall,
and the results were intriguing. "We actually saw great
improvements in performance on all applications compared with our
legacy direct attached storage," he says. "This was most noticeable
on file servers." Mittal currently has several IP storage upgrade
projects that are awaiting approval.
Moving to consolidation
@31941 Healthcare facilities are notorious for their storage
demands. It's not just a matter of patient records, but also a
proliferation of high-resolution digitized images, such as X-rays,
MRIs and CT scans. For the Children's Hospital of Los Angeles
(CHLA), these storage requirements were exacerbated even further
with sophisticated drug and treatment research endeavors.
Unfortunately, CHLA was faced with two important storage problems:
a proliferation of servers running disparate medical applications
and a complete lack of centralized storage. "When I started in
March of 2005, the hospital was on a Novell [Inc.] environment with
all direct attached storage to the servers which were running out
of room -- 'out of space' messages were occurring daily," says
Randy Ferber, senior project manager at Computer Science
Corporation (CSC) [providing technology services to CHLA]. The
exact amount of DAS was not entirely clear.
It was obvious early on that the centralization and sharing of a
SAN would be essential before CHLA could ever manage its storage
effectively. Ferber spent over a year researching SANs for the
hospital. "Fibre Channel presented a lot of challenges that frankly
I didn't want to afford," he said. "And how much performance do you
really need?" Storage performance had been terrible because the
storage devices were full, so Ferber concluded that adequate
results could be realized without the expense and overhead of Fibre
Channel -- a decision that eventually led to the deployment of two
LeftHand Networks Inc. IP storage SANs connected by an optical
fiber link. Ferber reports that the initial installation was
problem free and took about three days.
Today, 19 TB is currently deployed in IP storage (that figure is
expected to double in 2007) and iSCSI storage has totally replaced
the decentralized DAS architecture; bringing cost and management
savings to the enterprise. "I know I save 40% of what a Fibre
Channel [SAN] would have cost," Ferber says. "I showed a return on
investment in less than a year." Additional iSCSI storage can
automatically configure and grow volumes as needed, simplifying the
management needs for IP storage. As more users embrace centralized
SAN storage, Ferber is systematically removing Zip drives and other
decentralized storage devices.
The next big push for CHLA's storage infrastructure is to
eventually eliminate tapes. Although tape use has declined with the
adoption of IP storage, it is still an essential part of long-term
data retention for children's medical records (currently 21 years).
Still, Ferber expects tape use to fall up to 90% as RAID and
disk-to-disk backup become more prominent.
The enterprise is noticing
IP storage was considered to be a low-end technology only a few
short years ago -- a simple answer to shared storage in the SMB.
But it's clear that IP storage, in the form of iSCSI, has captured
the attention of larger organizations. Ultimately, traditional FC
SAN deployments are expensive to deploy, cumbersome to configure,
and difficult to expand. Conversely, independent NAS and DAS
deployments can easily become impossible to manage and protect.
Users see iSCSI as a cheaper and easier SAN technology that can
grow rapidly while still providing solid storage performance for
users. IP storage is also proving itself in high-end tasks like
backups, remote replication, snapshots and RAID. Although it's
still not the predominant choice for transaction-centric data
centers, IP storage is finally taking its place as an important
storage technology in the enterprise. ***