Even small Fibre Channel SANs require IT talent with specialized knowledge to configure and manage them and can be expensive to create. But with the cost of Gigabit Ethernet server NICs undercutting the cost of Fibre Channel HBAs and the precipitous drop in the price per port of Gigabit Ethernet switches, interest in IP-based storage networks is growing. The Internet Engineering Task Force's (IETF's) new iSCSI standard for carrying SCSI commands and storage data over IP networks is gaining broad industry support, setting the stage for the introduction of IP-based SAN storage solutions. Vendors such as IBM, Cisco Systems, and Nishan Systems have already introduced iSCSI-based products, and industry observers expect HP to jump in soon. Look for other vendors to follow.
In the short term, 2Gbps Fibre Channel technology will predominate, especially for applications that demand guaranteed packet delivery or the utmost in performance. Fibre Channel technology is very reliable, and most larger IT shops are likely to let iSCSI products shake out before adopting them. Early on, 1Gbps IP-based SANs will appeal to small organizations that have less-demanding applications and that need to rein in their storage-management workload but can't afford specialized IT talent, management tools, and Fibre Channel hardware. We'll also see mixed Fibre Channel—and IP-based storage-network environments.
Over time, however, IP-based storage networks will gain favor as they develop a track record. One reason for this expectation is that technology typically advances more quickly in the Ethernet world than it does in the Fibre Channel domain. For example, 10 Gigabit Ethernet products debuted this year, whereas Fibre Channel just recently made the leap from 1Gbps offerings to 2Gbps offerings.
One hurdle that NAS and IP-based SANs need to overcome is TCP/IP processing overhead. As IP storage networks are asked to carry increasing amounts of data, this overhead can significantly affect the performance of the servers or appliances that do the processing. Existing Gigabit Ethernet server NICs can't off-load this processing, but Alacritech has introduced the Alacritech 1000x1 Single-Port Server and Storage Accelerator, which off-loads TCP/IP processing from the host processor. Although Alacritech has set no retail price for the card because initial shipments of the product are going directly to system manufacturers, a company representative says that system manufacturers can acquire the card for less than the cost of a 1Gbps Fibre Channel HBA.
Making a Decision
When deciding on your future storage strategy, your applications' requirements and the goals you've defined for your storage initiative will determine the solution that best meets your needs. For example, if you'll be mining data from a relational database, a SAN's high-performance block-level access is an obvious choice, whereas a NAS solution is more appropriate for serving Web pages and for other file-service tasks. If high availability is a top priority, you'll need to select a product that's been tested with your clustering solution.
If you decide on a SAN, you'll want one that permits a network topology with redundant data paths. Although vendors are heeding customer demands to make SAN hardware and software more interoperable, assembling your own solution remains a difficult proposition. Even if you have the inhouse expertise, acquiring all SAN components from one provider is still the safest approach. But if you know you'll want to add third-party products to that SAN in the future, your best bet is a standards-compliant offering that's been certified with a wide range of products. And regardless of whether you select a NAS or a SAN solution, don't forget to investigate which antivirus and backup offerings vendors have certified, particularly if you're considering a product that uses a proprietary OS.
End of Article
Prev. page
1
2
[3]
next page -->
