Most Storage Lies Fallow

Two thirds of the respondents to Byte and Switch's latest poll say their storage utilization is less than 60 percent -- indicating that most storage systems are still provisioned with more capacity than is needed.

Of 100 respondents to our July poll, 37 percent said the current average utilization of their enterprise storage systems was between 40 and 59 percent; 19 percent said it was between 20 and 39 percent, and 9 percent put it at less than 20 percent. Meanwhile, 26 percent said their utilization rate was between 60 and 79 percent, and 9 percent answered that it was 80 percent or more.

A plurality of those surveyed (40 percent) said their free disk space would last for the next three to six months. Another 28 percent said they were set for seven to 12 months, and 15 percent said it would last for a year or more. Just 18 percent said they'll run out of disk space within two months or less.

The problem of matching up storage capacity with what's actually used has always been a headache for IT administrators. The strategy many have pursued is to overestimate the amount of disk that's required for a given application, with the idea that it's better to have too much storage than too little. The problem with this overprovisioning is that some -- or most -- of the expensive disk storage that's been deployed sits around doing absolutely nothing [ed. note: rather like Jack Osbourne].

To address this particular pain point, storage vendors have started offering "storage-on-demand" programs, which are supposed to let customers pay for only as much storage as they use in a given month.For example, EMC Corp. (NYSE: EMC) introduced OpenScale this month. The program lets customers install standby storage resources and then instantly turn them on when needed. A special billing system keeps track of exactly what's been used, including storage, SAN switches, and software. Hewlett-Packard Co. (NYSE: HPQ) and IBM Corp. (NYSE: IBM) offer similar storage-on-demand programs (see EMC Snoops on Demand).

Taking a slightly different skew on the capacity-on-demand concept, startup 3PARdata Inc. has introduced a feature it calls Thin Provisioning. This lets users create virtual volumes on a 3PAR system without actually purchasing or installing the entire amount of disk storage; if more capacity is needed, it can be added later (see 3PAR Spins Disk Trick).

Being able to add storage incrementally would certainly alleviate some of the problems IT administrators face when trying to free up more disk space. Some of the top strategies for handling storage growth, according to our poll, include: reallocating underused storage resources (21 percent); making sure the IT budget accounts for additional disk purchases (20 percent); deploying cheaper disk storage (19 percent); and setting user storage quotas (13 percent).

Todd Spangler, US Editor, Byte and Switch