Good things are in store
- By John x_Zyskowski
- Sep 11, 2000
After years of mostly missing the mark, storage vendors are delivering a
brand-new kind of product that is finally delivering the goods for storage-area
networks. These so-called SAN appliances are designed to solve the toughest
problem that agencies face when building SANs — making storage devices and
servers from different vendors work together.
Two of the most recent introductions are from Dell Computer Corp. and
storage networking vendor Gadzoox Networks Inc. Both companies will begin
shipping their SAN appliances to customers this month. The appliances are
specialized file servers that connect directly to the SAN and organize all
the storage devices into one large pool of communal storage, which is then
available to any server connected to the SAN.
A SAN is a high-speed, special-purpose network that connects servers
to storage devices. Network switches in the SAN enable any server to access
data on any storage device, at least theoretically, without affecting the
regular local-area network.
"This is the missing link in Fibre Channel SANs," said Steve Duplessie,
senior analyst with market researcher Enterprise Storage Group. "The biggest
problems users face are complexity and interoperability issues. At a fundamental
level, that's what the SAN appliance addresses."
SANs were supposed to solve the problems of traditional storage architecture,
in which storage devices are attached directly to servers via SCSI or some
other standard interface. Among the problems was that too often storage
capacity attached to one server went unused while another server on the
network might quickly outgrow its available capacity.
By unshackling storage from servers, Fibre Channel-based SANs would
minimize inefficiency by letting IT managers easily add, reconfigure and
reallocate communal storage resources in the SAN as needed to keep up with
growing or changing storage requirements.
But most of the current SAN management software only works properly if all
the storage devices are from the same vendor and if the servers connected
to the SAN run the same operating system. Even then, SANs are fairly tricky
to set up and manage.
Analysts expect that SAN appliances will help overcome these limitations,
if not entirely with this current wave of new products, then certainly soon.
Besides being the central point for managing the multiple storage arrays
and switches in the SAN (see diagram), SAN appliances are also designed
to be simple to buy, install and maintain. For example, Dell's new PowerVault
530F SAN appliance comes in only one Intel Corp. Pentium-based configuration
and is pre-loaded with the SAN management software that acts as the brains
of the SAN. Dell uses SAN software from StorageApps Inc.
"The beauty of the SAN appliance is that it doesn't require any additional
software on the servers," said Bruce Kornfeld, Dell's director of marketing
for PowerVault storage.
One important benefit of the Dell SAN appliance is that users can create
a disaster-recovery solution by deploying two PowerVault 530Fs in different
locations. The local PowerVault 530F and its set of storage arrays act as
the primary storage resource, while an exact copy of the data can be written
in real time and maintained by a PowerVault 530F and arrays at another location.
This remote mirroring can take place over the Fibre Channel SAN at distances
up to 10 kilometers (6.2 miles), or over even greater distances using IP-based
Dell's PowerVault 530F also lets customers organize multiple storage
arrays into one pooled resource, or what the industry calls "storage virtualization."
However, for now the PowerVault 530F only does that with Windows NT/2000-based
servers and storage arrays. The PowerVault 530F began shipping last week
and lists for less than $50,000.
Unlike the Dell product, the two SAN appliances that Gadzoox Networks
will begin shipping at the end of this month will deliver storage virtualization
in heterogeneous environments. "As long as the server has a Fibre Channel
card in it and can plug into the switch, I can give it access to the storage
pool," said Erik Ottem, director of solutions marketing at Gadzoox.
The Gadzoox appliances come in two models and can support various vendors'
storage devices and servers running Linux, Unix, Windows NT/2000 and Novell
Corp.'s NetWare, Ottem said. Both models include SAN management software
from DataCore Software Corp.
The Gadzoox Axxess 200 bundle includes an appliance that has two Intel
Xeon Pentium III processors and a Gadzoox Capellix 2000 Fibre Channel switch,
which supports up to nine system connections. It lists for $50,000. The
Axxess 400 bundle includes an appliance that has four Xeon Pentium III processors
and comes with a Capellix 3000 switch, which can support up to 27 system
connections. It lists for $110,000.
What the current versions of the Axxess products don't provide is the
remote copy and data snapshot capabilities for creating a remote disaster-recovery
solution. Those features will be available in the Axxess products around
the end of year, Ottem said.
There's little doubt that vendors will continue to focus their attention
on delivering more functionality to the SAN itself. By supporting data virtualization
and remote mirroring and recovery capabilities, SAN appliances offer traditionally
high-end data processing features for a lot less money. By being relatively
simple to buy and operate, they also address another key piece of the equation:
"With the cost of storage coming down 40 percent a year, storage is cheap
to buy but expensive to manage," said Gary Wright, Compaq Computer Corp.'s
director of marketing for enterprise storage software. "And people expenses
are going up, not down. You have to get more productivity from the people