Beat the storage standardisation problem
- Posted:
- 16:44 30 Mar 2004
- Topics:
- Storage Management | Internet | Business Continuity
Problems with standardisation in
storage networking are leading businesses to abandon cross-platform
IP initiatives to concentrate their spending on one
supplier.
Firms are now looking to reduce the number of locations where they
store data in an attempt to cut costs and boost security. This can
be achieved by investing in high-end security and storage systems
at a smaller number of datacentres as part of business continuity
plans.
Several storage protocol options are available, the most popular
being storage area networks. Sans have played a key role in
enabling firms to share information in real-time, across different
local departments and between corporate units across different
continents.
A San is typically based on the Fibre Channel protocol, but can
also use protocols such as asynchronous transfer mode, Fast
Ethernet (100mbps) and Gigabit Ethernet, with 10 Gigabit Ethernet
now here too.
Fibre Channel has a connectivity reach of only 10km and the maximum
data throughput is only 2gbps. In the 1990s this performance was
seen as very satisfactory and, in truth, was probably the only real
solution for many. But the Fibre Channel protocol is straining as a
result of businesses connecting more sites over greater distances,
together with vastly increased amounts of data to push through and
store.
Gigabit Ethernet
The arrival of technologies such as Gigabit Ethernet means IT
directors now have a viable alternative to Fibre Channel. Even
though the first Gigabit Ethernet solutions were not as fast as
Fibre Channel, their reach was potentially much further than the
10km limit.
Along with the greater distance it supports, Gigabit is a
well-understood technology. The fact that corporates already rely
on Ethernet technology for their basic networking means that a San
built using 10 Gigabit Ethernet looks much more attractive to firms
than Fibre Channel-based technology.
Analyst IDC has estimated that use of Gigabit Ethernet network
connection ports will increase more than fivefold in 2004, so
companies buying these ports will want to ensure their investment
in Gigabit Ethernet is fully realised by adopting or expanding
towards 10 Gigabit Ethernet for their storage needs.
The IP combination
The biggest shake-up in storage today is the widespread adoption of
Internet Protocol and increased use of the internet. IP potentially
makes the reach of a San infinite, therefore making it possible for
companies to link datacentres cost effectively - not only between
cities, but also across continents.
Gigabit Ethernet technology is combined with IP to form yet another
new storage protocol called internet SCSI. This is now seen as the
ideal way for companies to secure their stored and shared data over
long distances. Following a painstakingly slow standards
ratification process, commercial iSCSI products are now here.
Not surprisingly, take-up of this new storage technology has been
slow. According to a recent survey of IT departments by supplier
body the Storage Networking Industry Association (SNIA), fewer than
4% of users have begun to experiment with iSCSI. However, 25% of
survey respondents expected to deploy iSCSI within the next
year.
Implementation problems
Protocol technology, whether it be Fibre Channel, Gigabit Ethernet
or iSCSI, is only part of the problem IT directors face when
implementing a San.
Technically it is still complicated to design and implement a San
and many companies need third party help to make sure they build
the resilience they need into the system.
One problem is that storage products from different manufacturers
are incompatible, making it difficult to manage a storage
infrastructure easily. Centralised management of a San through a
single management interface increases efficiency. It is possible to
manage and support hundreds of servers and devices as a single
entity. This lowers the cost of storage management on a per unit
basis, and increases the functionality available to network
administrators - although for many companies this target has turned
out to be difficult to achieve.
Progress has been made, albeit slowly, driven by the SNIA. The SNIA
has developed a standard called SMI-S (Storage Management Interface
Specification) for storage architecture which is designed to manage
storage from different suppliers - and the major suppliers appear
to be adopting it. SMI-S is a set of common models and protocols
designed to let storage management applications control storage
devices made by different hardware suppliers.
Supplier storage products
In February, as part of a raft of product launches around its
information lifecycle management strategy, EMC said it would add
support for the SMI to its management software and add SMI-S
compliance to its Symmetrix and Clariion products.
Last October, Hitachi signed a deal with AppIQ, a storage
management company, to integrate AppIQ's storage authority
management software into its own Hicommand policy manager over the
next two years.
Through the agreement, Hitachi's customers will gain the ability to
manage devices using the Storage Management Initiative
standard.
Single-supplier standards
Although SMI-S has gained wider acceptance among suppliers and is
becoming incorporated into products, users appear to be overcoming
storage incompatibility by standardising on the products and
services of one supplier.
John McArthur, group vice-president of storage research at IDC,
said, "International companies are linking together datacentres for
data availability, colla-borative working, or business
continuity/disaster recovery.
"However, many cannot afford to manage the complexity, costs and
potential risks associated with involving multiple storage
suppliers and telcos. So, instead they are seeking a single trusted
partner who can provide the complete storage network
infrastructure."
One example of the type of service on offer is the recently formed
alliance of Dell, EMC, Nortel Networks and BT. The firms are
inviting customers to sample the long-distance business continuity
network they have set up at Dell's European headquarters in
Ireland.
Using the storage boxes and network switches from this alliance,
customers can implement a San between large datacentres from
between £105,000 and £385,000 (list price, including
"gold level" 24x7 support).
The price of shifting the data through the right data pipe is
additional to this hardware cost. The involvement of BT in this
alliance shows that telecoms companies realise that the price of
bandwidth has dropped so much they must move quickly to make up
lost revenue by offering consultancy and support, both before and
after the implementation of networks such as Sans.
San basics
- Sans can be based on Fibre Channel protocol, ATM, Fast Ethernet or Gigabit Ethernet
- Fibre Channel is short range and relatively slow; Gigabit Ethernet boasts a slightly longer range
- Internet Protocol can extend the reach of Sans to global distances
- The next big thing is iSCSI, a standard combining global Ethernet with IP.
