Mid-range arrays provide much-needed storage relief for organizations. They cost a lot less than their high-end counterparts.
They meet the performance requirements for most Windows and Unix applications. They provide flexibility for administrators to mix and match Serial ATA and Fibre Channel disks and configure various types of RAID groups in the same frame.
They also often include snapshot and copy features with their management software.
Yet, we've all seen the Hertz car commercials where an individual rents a car from another agency. After renting it, the person discovers his rental experience is "not exactly" like renting a car from Hertz. Implementing mid-range instead of high-end arrays can be a lot like that.
Once permitted into a company, they start to appear everywhere. This adds the job of inventory taker to the storage administrator's list of responsibilities. The location of each mid-range array must now be tracked along with documenting which Fibre Channel switches it is connected to and how much storage is allocated and available to each one.
Control becomes an issue. The department that bought the mid-range array often wants the final say on their storage and who uses it. For those willing to share, allocating it requires a series of technical and political manoeuvres. Department heads need to give approval, accounting wants an allocation notification, and SAN changes need to be completed before even 1GB of storage is assigned to an application.
Vendor support also changes. A smiling technician carrying a tool bag shows up to configure the high-end array; a CD and a phone number for someone in Indonesia typically accompanies the arrival of a mid-range array.
Users should not confuse the two. Mid-range arrays deliver high-end performance and capacity at mid-tier prices, but lack the more sophisticated software, availability and high-touch features that high-end arrays deliver. And with companies always trying to do more with less, having more mid-range arrays may not exactly deliver more of what they thought they were buying.
Jerome Wendt currently works as both a storage engineer and storage analyst