Many have positioned iSCSI and Fibre Channel as competitors. However, many major server and storage vendors prefer the iSCSI storage area network (SAN) as an adjunct to Fibre Channel SANs. Both iSCSI and Fibre Channel technologies solve the same technical problem of networking block storage. The differences are in the details. There are five areas to consider when picking a SAN technology:
Learn how to choose the right type of SAN.
Many SMB IT managers are likely to come up against the limitations of servers with integrated storage or DAS. They may need more capacity, higher performance, better utilization of storage or advanced features such as replication, snapshots or thin provisioning.
The next obvious step is networked storage, often a SAN-based storage array. However, for the SAN beginner, the assortment of choices in host bus adapters (HBAs), optical cabling, Fibre Channel switches and storage systems can be a bit overwhelming. The SAN-in-a-box is a simple solution for these new SAN admins.
After you go through the purchasing and deployment process to implement your new SAN, you'll need to migrate all of your data to the new platform and switch off the old file servers or arrange some downtime to remove those redundant direct-attached disks.
When migrating your data from DAS to SAN, consider the following: how to move the data from file servers; how to move your database-type information; and whether to go to that final mile and host operating systems on the SAN, so your servers don't need any local disks at all.
Learn more about moving data from DAS to SAN.
Storage environments in SMBs can range from a few servers to hundreds of servers. Entry-level SANs can be built using iSCSI and general-purpose Ethernet technology. Larger storage environments can leverage Fibre Channel. Or, in the future, they can use Fibre Channel over Ethernet, combined with Data Center Ethernet, which is what Cisco Systems calls premium, low-latency, lossless Converged Enhanced Ethernet.
There are a lot of options to choose from. However, there are a number of things that you should consider when choosing a SAN switch, regardless of if it is for iSCSI, FCl, FCoE or even InfiniBand-based SANs for SMB environments.
SANs can be temperamental. This is especially true when they're poorly managed. Troubleshooting is tough because a good design is not always obvious and Fibre Channel standards are just loose enough to make interoperability a concern.
Learn more about troubleshooting SANs.
SMBs frequently have to deal with disparate SANs. For example, many companies start with an entry-level system and later must add a larger, more sophisticated one. SAN consolidation usually has two different meanings depending on the point of view. It either means reducing the number of multiple separate SAN fabrics (networks) to a more manageable number, or doing the same to multiple separate SAN storage systems.
The value of SAN consolidation comes from significantly reduced management. It is intuitive to see that it is far easier to manage a consolidated SAN than multiple SANs. Consolidated SANs also benefit from fewer software licenses, lower maintenance, reduced real estate, power, and cooling.