There is debate about that. Many customers may prefer to have just
one storage system, avoiding specialized storage systems, like
network attached storage (NAS) for
file-based access or a complicated block-based storage system,
such as a
RAID array. A unified [or multiprotocol]
storage platform combines both modes to offer a single solution
-- that's the advantage that you hear most often. Many customers
embrace the flexibility of
unified storage, meaning that they can buy
and deploy such a platform as just a file-based system. At some
point later, they could redeploy the unified storage platform in
a different usage mode. Users can decide what the storage system
will do for them at any point in time.
@31875 Another benefit is simplicity, which is also a matter of
debate. Some
block storage systems can be complicated
because of all the functionality they provide, along with the
capabilities and technologies they employ. Most NAS systems
providing only
file-based access are very simple. Vendors
have made a "competition" out of NAS deployment by vying to
offer the shortest deployment time. A block storage deployment
takes significantly longer. The challenge is to merge the
complexity of block storage with the simplicity of NAS in a
single platform. In reality, a majority of the unified storage
systems are really NAS that vendors have added block mode
support for.
But the issue of simplicity is even more complicated. A large
percentage of NAS-centric unified storage platforms are
iSCSI only -- vendors have basically taken a
NAS system and added an iSCSI target-mode driver that executes
the SCSI target-mode commands used against a particular volume
(or
LUN) dedicated to a specific use. In
practice, the unified storage systems built on a NAS base with
only iSCSI support probably would be simpler from a management
standpoint. Those unified storage systems that add
Fibre Channel capabilities are natively more
complex because there are more high-end enterprise capabilities
to contend with, compared to a typical iSCSI environment, such
as masking or LUN affinity. So the actual "simplicity" depends
on where the particular product came from, how it was designed
and how it operates now.
Listen to the
unified storage FAQ audiocast.
Go to the beginning of the
Unified Storage FAQ Guide.