Clash of the SAN standards looms

The IP-based iSCSI is growing as the technology of choice for those seeking a cheaper network storage solution, but Fibre Channel isn't finished yet

In New Zealand, iSCSI, the emerging IP-based standard that runs over Ethernet, is gaining momentum as the technology of choice for storage-area networks (SANs). However, the predominant Fibre Channel SAN medium is well-entrenched in the user base and is still being implemented for new SANs.

Last month, for example, the Ministry of Fisheries selected a Dell-EMC system for its long-planned SAN. The $300,000-plus Fibre Channel SAN will be part of a new IT environment at the ministry, which will also include a document management system from Meridio.

The RFP (request for proposal) for the SAN, issued last year, noted that iSCSI (Internet Small Computer Systems Interface) is gaining traction, but expressed a preference for Fibre Channel — and that was the solution chosen.

However, several other government departments have recently implemented or selected iSCSI SANs. One, the Civil Aviation Authority, chose an iSCSI-based EMC system in 2005, to replace an ageing HP Fibre Channel SAN. More recently, the Tertiary Education Commission selected a Network Appliance iSCSI SAN, which will be supplied by integrator Infinity Solutions.

The Nelson-Marlborough District Health Board currently has an RFP out for a new SAN and the preference is for Fibre Channel for production servers, but iSCSI will be considered for non-production servers.

Clearly, iSCSI is making inroads into the market, though Fibre Channel is not only well-established in existing SANs but is still being implemented in many greenfield SAN projects.

So what’s all the buzz about iSCSI? It’s mainly to do with savings, both in terms of equipment and when it comes to staff. As iSCSI runs over Ethernet, the infrastructure associated with Fibre Channel SANs doesn’t have to be installed when getting an iSCSI SAN. Also, because existing IT staff are likely to already be familiar with Ethernet, training and support from storage vendors is far less of an issue. For these reasons, iSCSI SANs are being pushed by storage vendors targeting smaller organisations that may not have considered a Fibre Channel SAN because of cost and staffing issues.

The consensus among industry-watchers is that while iSCSI has much utility for small- and medium-sized SANs, large clusters of devices that require networked storage, such as datacentres, are better off with Fibre Channel.

Chuck Hollis, EMC’s vice president of technology alliances, recently told that “iSCSI hasn’t cracked the big time”, because large organisations currently spend several billion dollars a year on Fibre Channel technologies. “And it doesn’t look like [that’s] going to change in the near future”.

Most large organisations with installed Fibre Channel SANs aren’t in a rush to replace them, Hollis says.

However, others believe iSCSI is gaining significant momentum.

Analyst firm IDC predicts iSCSI will have a compound annual growth rate of 73% per annum between now and 2010, and that the iSCSI market will be worth $US5.1 billion (NZ$7.1 billion) by then.

Another analyst firm, The Enterprise Strategy Group, says there are more than 25,000 iSCSI SANs deployed worldwide. The company recently surveyed 500 organisations on their storage practices and intentions, and found that 17% had adopted iSCSI and that another 20% plan to in the next one-to-two years.

Graham Penn, IDC’s Asia-Pacific associate vice president for storage research, says “no storage vendor will claim to prefer Fibre Channel over iSCSI — most do both and are happy for them to co-exist”.

For small- to medium-sized organisations, iSCSI is an attractive option because of the equipment and staffing reasons mentioned above, he says.

“The cost-difference [when it comes to] implementation isn’t that great — the lower labour costs are the real differentiator.”

However, when storage needs are larger, such as with datacentres, new SANs will still be mainly be of the Fibre Channel variety, he says.

He cites, as an example, Citibank in Singapore, which recently built a new SAN to link two datacentres, using Fibre Channel.

The bank already had Fibre Channel SANs in other parts of its operation “and had no hesitation in staying with Fibre Channel”.

Security is an area where Fibre Channel has an edge over iSCSI, because of the latter’s use of IP, Penn says.

“Some organisations will choose to stay with Fibre Channel because of security issues. With iSCSI, you can use encryption and other security measures, but Fibre Channel is even safer”.

(Some large organisations use Fibre Channel-over-IP for networking data over long distances. But, for local storage networks, Fibre Channel avoids the exposure that using IP brings.)

Penn says that in 2010 the ratio of Fibre Channel to iSCSI SANs globally is likely to be 70% to 30%.

“While both will continue to grow, iSCSI won’t push Fibre Channel out of the mainstream,” Penn says.

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