Storage /

Dreaming of an island

By Mike Karp
Network World Storage Newsletter, 08/29/01

In today's complex IT environment, your data is frequently remote from the processes that use them. If you're lucky there is some discernable logic as to how the storage topology is laid out, but if you're like most of us, the storage is scattered all around the network resulting in what is often termed " islands of storage. "

Now many things belong on islands (palm trees, beaches, and me drinking a pina colada all come to mind), but stored data belongs elsewhere. While that " elsewhere " may be a question of philosophy, the point is that information is both remote (which is not a bad thing) and scattered among these localized storage islands (which in almost all cases IS a bad thing).

Storage islands come in many forms: they could be disk and tape devices scattered around a storage area network; racks full of Network Applications Support appliances; RAID boxes directly attached to servers; or a mixture of devices at a remote site. Most likely, if you work for a company that generates a fair amount of data, you contend with a hodgepodge of devices.

Whenever information is remote from the user, switches and routers appear somewhere along the critical path between user and data. Switches are typically found where networks intersect with one another, forming the gateway between defined subnets - between a LAN and a SAN, for example. Routers examine a packet's header information to determine the intended destination and then match that against an internal table to determine the next point in the route. Increasingly, we are seeing " routing switches, " which incorporate routing functionality into switches.

There are many vendors that provide such products. Players in the mid-range include Brocade, Gadzoox, and Vixel, while INRANGE and McData make directors, which are larger switches.

One size never fits all, though. Consider the environment they have to service. The mix-and-match world of today's enterprise networks uses many protocols: you may be accessing data over a FibreChannel SAN, over an Ethernet LAN or a WAN using iSCSI, and even someday over newer technologies such as InfiniBand or FibreChannel-based Internet Protocol. The problem wouldn't merely be the scattered storage islands, but that they also have to be accessed in different ways. This can lead to some expensive infrastructure issues, not to mention added training, localized (but not centrally controlled) security, and redundant management tools that probably don't provide the same level of service across the corporation.

We have talked about most of these issues before, and suggested that reducing the number of elements under management by virtualizing the storage environment seems like a good way to go. DataCore and StorageApps would be delighted to speak with you if you want some information on this.

If you're shopping for switches you may not see many opportunities to economize in multiprotocol environments. This may soon change however, as a new generation of centralized switching devices is expected offer support for multiple protocols within the same box that would allow both file- and block-level I/O regardless of whether the storage is accessed via FibreChannel, SCSI over IP, or InfiniBand. Pirus Networks, headquartered in Massachusetts, looks to have its " Storage Utility Switch " out first, and seems to have played nicely with the others at the recent iSCSI plug-fest in New Hampshire. Others are sure to follow.

Switches that offer multiprotocol translation should offer you a way to easily hook up your users to those storage islands, and may even offer you a way to get to another sort of island altogether.

Alternatively, if instead of an island you are going to be at N+I, please stop by one of my sessions and say " hi. "