iSCSI brings networked storage to SMEs

Thanks to cost and technology issues, the benefits that storage networks bring have hitherto been largely restricted to large corporations. However, V Vivekanand says that SMEs can now take heart as iSCSI has opened the doors of networked storage to small and mid-sized businesses too

The increasing dependence on information and data to conduct business has transformed information into one of the most valuable corporate assets in today’s business environment. It has also spurred the growth of storage and in recent times the growth of networked storage. Most large organisations have benefited greatly from networked storage solutions.

However, it is worthy to mention that the need for critical information is not just restricted to large organisations, but is equally important for smaller enterprises. But until now storage networking has fulfilled its full potential only at the largest organisations, through the use of high-speed Fibre Channel Storage Area Networks (SANs) and advanced Network Attached Storage (NAS). The benefits of networked storage have only marginally reached small and medium enterprises (SMEs). They still continue to amass huge amounts of data in disparate silos of storage devices, which are often inaccessible and dispersed through out the organisation. In such environments storage resources and devices are vastly underutilised with individual user groups using their Direct Attached Storage (DAS) as their own file systems.

Why SMEs avoid storage networks

Why is it that smaller companies don’t avail of the benefits that come with networked storage using Fibre Channel technologies? There are numerous reasons for this:

• Fibre Channel technology has been prohibitively expensive for small- and medium-sized businesses.
• There are significant interoperability issues with Fibre Channel components.
• Fibre Channel and IP have existed as separate networks.
• Fibre Channel expertise is a scarce commodity and therefore expensive to obtain.
• Despite its wide bandwidth, Fibre Channel is distance-constrained.

Besides, small and medium sized organisations often find themselves in an ever-larger inventory of DAS that has accumulated as ‘stranded’ storage. This ‘stranded’ storage is often not SAN-worthy, which means that it is so inexpensive that the cost of connecting to a Fibre Channel switch is higher than the value of the storage itself. These are some of the prohibitive factors that stop small and medium enterprises from going in for storage networks.

The iSCSI answer

However, even as they concede to the fact that consolidating storage resources will deliver definitive advantages in the face of expensive Fibre Channel technology, which makes network storage prohibitive, the iSCSI (Internet Small Computer System Interface) protocol comes as a breath of fresh air for small and medium companies. iSCSI is dramatically changing the networked storage landscape and these changes are expected to accelerate. According to IDC, the iSCSI market will jump from $216 million in 2003 to over $1 billion by the end of 2004, and almost $5 billion in 2007. Among the factors driving the boom are the spring 2003 ratification of the iSCSI specification, the increasing prevalence of Gigabit IP LANs (Local Area Networks), and the fact that the CPU performance of today’s servers is able to absorb the TCP/IP processing overhead that was once regarded as a serious inhibitor to iSCSI acceptance.

When we look at implementing a fibre channel network as against iSCSI within the small and medium enterprises segment, it seems logical for them to embrace iSCSI for storage consolidation. This is because small and medium businesses are price-sensitive and after spending $2,000–$3,000 per server they would be understandably unwilling to shell out $2,000 per server to connect them to a Fibre Channel SAN. On the other hand, they can install a free iSCSI device driver on the server’s existing fast Ethernet or Gigabit Ethernet card and front ending Fibre Channel storage with an IP storage switch. This makes iSCSI an ideal solution for those stranded servers, which can now use existing IP network access for block data access or back-up.

Further, interoperability has been a major issue in existing Fibre Channel technologies. Therefore, the question whether point solutions from different vendors can talk to each other within an enterprise storage environment has become one of the most important criteria for choosing solutions rather than price, performance and functionality. On the other hand, iSCSI promises universal connectivity through the SCSI parallel interface. That connectivity is even extending to Fibre Channel SAN islands, which, in the wake of iSCSI’s growing popularity, are commonly being connected via IP networks.

iSCSI & Fibre Channel

Now, does that mean iSCSI will replace Fibre Channel? Not quite, according to most experts. Rather, they view both of these as complementary technologies. With Fibre Channel technology being firmly established in data centre environments, it would not be prudent for them to rip off existing infrastructure. iSCSI may be most attractive to companies with no Fibre Channel investment, but the benefits of iSCSI can be realised by companies that already have Fibre Channel infrastructure. Such companies can benefit from iSCSI when they need to centralise server storage and Fibre Channel is not a cost-effective option.

Further, as iSCSI utilises the full potential of existing IP infrastructure within a company to provide a SAN environment, small and medium companies will no longer have to think hard to find prohibitively expensive Fibre Channel experts to implement and manage the storage environment. They can now use the existing IT infrastructure and expertise to bring the iSCSI SAN environment to their organisations. Because iSCSI uses existing IP infrastructure to deliver SAN, this translates into many cost benefits to user organisations, who:

• Do not have to extensively upgrade existing hardware to support their iSCSI storage solutions.
• Do not have to train employees on Fibre Channel technology to the tune of $1,000 per day.
• Are able to implement their solutions more quickly than they can with other protocols.

Besides, organisations using Fibre Channel SAN find obvious limitations in extending storage connectivity over wide areas, due to Fibre Channel’s 10 km distance limitation, whereas iSCSI users can use iSCSI links to any distance, which is limited only by the IP networks themselves. Besides, existing Fibre Channel SAN can also be extended or interconnected over IP networks using iSCSI.

These apparent benefits have led many leading software and networking vendors to provide free iSCSI drivers and iSCSI software in their product offerings. Therefore, small and medium sized businesses that were previously excluded from the benefits of storage networking are now in a position to fully realise these benefits through the use of iSCSI-based SANs deployed across IP networks. Further, iSCSI presents a cost-effective opportunity to deploy storage over IP while leveraging IP infrastructure features, performance, QoS (Quality of Service) capabilities, network management, end-user expertise, and economics. Moreover, it is complementary to existing SANs, increases the number of storage access points, and enhances consolidation opportunities. iSCSI can be used for many applications, including database management, mail serving, back-up, and streaming media.

The author is director sales at Hitachi Data Systems, India. He can be contacted at vivek.anand@hds.com