Given the perpetual growth of data storage requirements, the marriage of IP and SCSI to create a new storage networking solution is a welcome development.

The emergence of the Internet SCSI protocol, or iSCSI, allows companies to take advantage of the IP protocols for their networking requirements while relying on SCSI technology to provide data storage. The joining of these two common technologies promises to offer a better network storage option for many companies.

Before you jump on the iSCSI bandwagon, however, weigh the features and potential advantages of the technology against your needs to determine whether it's right for your organisation. Let's take a look at what iSCSI has to offer, including the features that are making it an increasingly attractive network storage option.

Overview

iSCSI is a protocol that enables the transport of storage block data over Ethernet networks via IP. In contrast to network attached storage (NAS), which offers file-level access to data, iSCSI provides block-level access, which, proponents say, can offer much-improved performance. Before iSCSI was introduced, the only way to transport network data for storage was in file I/O formats. The introduction of block I/O storage data transport can offer performance benefits because it removes the need to translate to file I/O formats. Essentially, iSCSI represents a storage area network (SAN) solution over IP networks.

One of the biggest attractions of iSCSI is its promise of linking storage facilities over long distances. The expectation is that the technology will facilitate the rise of the SAN market by offering new capabilities and better performance of storage data transmission. Because iSCSI uses standard Ethernet switches and routers to move data and link storage facilities over any distance, companies won't have to upgrade their infrastructure in order to implement iSCSI.

Advantages

Proponents of IP storage claim that it offers a number of advantages over other alternatives, including lower infrastructure and training costs and improved performance. In terms of how readily iSCSI will be adopted, cost considerations will certainly weigh heavily, especially in light of the current economic climate. Companies shopping for a network storage solution will be more apt to look seriously at one that will allow them to increase their storage without forcing them to take a big hit in the wallet.

Use of existing infrastructure

Perhaps iSCSI's biggest edge over competing technologies is that it takes advantage of existing IP network infrastructure. This will translate into cost savings in significant ways:

• Companies won't have to pay a lot of money to upgrade existing hardware to support the iSCSI storage solution.
• Companies won't have to extensively train employees on a new technology.
• Companies will be able to implement the solution more quickly than they would be able to upgrade to other solutions.

Because the essential infrastructure is already in place and is a familiar one that IT professionals have already mastered, iSCSI offers an easier implementation path that won't require a huge investment in terms of hardware, training, and labour.

Other important considerations

• Reliability: The IP infrastructure that iSCSI relies upon has a proven transport track record, so companies can move data to storage over it with confidence.

• Pooled storage: Unlike some solutions that create isolated data repositories, iSCSI can create shared storage. Users will thus be able to connect multiple storage devices to multiple servers to expand storage and streamline storage management.

• Data storage over great distances: Data can basically be stored efficiently anywhere that Internet access is available. Users will have remote access to sites potentially spread over a wide geographic area, which opens up a number of storage and data backup options. Users will be able to store and access data no matter where they are.

• Performance: iSCSI promises to improve performance by offering block-level access to data rather than file-level access. Performance will also be enhanced by offloading some of the SCSI processing to the NIC. Although this could actually be handled with existing NICs through software, the CPU burden will likely be lessened with the introduction of new devices, including new NICs that will take over the processing burden.

Weighing the options

Overall, iSCSI appears to be an attractive network storage solution. If you need to expand your storage and are looking for a cost-effective option, iSCSI may be the way to go. Companies are likely to adopt iSCSI over other solutions simply because it will potentially cost far less to implement and will not require a lot of staff retraining.

Ultimately, however, you have to look at what your specific needs are in terms of storage. iSCSI makes a strong case for companies feeling the crunch of tightened budgets and companies that operate multiple sites spread over a wide area.

A number of networking hardware vendors now include iSCSI offerings in their product lines. These vendors' Web sites are good sources of information about the advantages of iSCSI vs. other options such as NAS and fiber channel. If you're in the market for a network storage solution, you might want to consult the resources at these sites: IBM, Adaptec, Cisco, and Intel. For a more comprehensive list of companies that offer network storage solutions, including iSCSI products, check out STORAGEsearch's iSCSI page.

As data storage requirements continue to expand, iSCSI will increasingly emerge as an efficient, effective, and inexpensive storage option.

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