Optical disk archiving slashes electricity bills

Optical disk media has many benefits for firms looking to archive

Using optical, rather than magnetic, disk media for long-term data archiving risks slow performance and extra floor space requirements, but can lead to considerably lower power bills, reckons a new report.

The assessment of the financial and environmental impact of using Plasmon ultra density optical (UDO) appliances compared with equivalent Sata hard-disk-based Raid arrays from EMC and NetApp, makes interesting reading.

Plasmon estimates that an organisation could reduce electricity costs by 97 percent over a ten-year period if they replaced Sata disks with UDO appliances. But the figures could be flawed in their assumption of consistent increases in utility prices and the efficacy of using removable media for disaster recovery purposes.

“We compared one of our removable media systems against two NetApp and EMC systems installed at two sites for disaster recovery. You could say that that is unfair, but if the objective is to reduce power consumption, UDO has the flexibility to take a different tack [by replicating data onto removable media] that hard-disk-based systems cannot,’ said Plasmon EMEA marketing director Steven Tongish.

“Even without the secondary DR site, the range of difference [in power costs] was around 20 times more for the Centera and eight to nine times more for the NearStore.”

Plasmon’s calculations consider the electricity required to power and cool the storage system - magnetic disks are constantly spinning and therefore need more electricity and cooling - and power any associated uninterruptible power supply (UPS). It used a mean of the current average per Kwh electricity costs for London, Tokyo and New York, which it estimated would rise by 6 percent per year over the ten-year period.

Nigel Ghent, EMC marketing director for the UK and Ireland, recognises that storage devices do use a lot of power and generate extra heat, but insisted the use of low-cost Fibre Channel components is helping to reduce energy consumption.

“EMC is also exploring technology that allows you do manage disk arrays and individual disks more effectively, so that idle disks can be powered down [to save electricity],” Ghent said.

Tongish said that a lot of enterprise customers assume that cheap, high capacity Sata disk configurations are good for long-term storage and compliance, but later re-evaluate their first impressions.

“Operational and initial acquisition costs are high, and there are compliance issues around the software-based write once read many (WORM) implementations that disk-based systems use – are they legally admissible? I’m not sure.” Tongish said.