High-capacity disk drives
Various experts periodically predict that magnetic disk is approaching its capacity limit, as the magnetic dots can't get smaller or be packed closer together. Yet engineers always find a new way to stuff more data onto a disk.
"Think of it as the relentless march of Moore's Law," says Peter Steege, enterprise disk segment marketing manager at Seagate Technology LLC. This year, perpendicular disk-recording technology, which stacks data vertically on the disk, is enabling Moore's Law.
Using perpendicular technology, Seagate expects to introduce a 1TB disk drive in 2007 with larger disks to follow. A 2TB disk drive within a few years is quite likely. Current enterprise-class SATA drives boast a 1.03 million hour mean time between failures (MTBF). The 1TB drives will have a 1.2 million hour MTBF. Other vendors, primarily Maxtor Corp. (acquired by Seagate) and Western Digital Corp., are expected to follow with similar capacity disks.
The 1TB enterprise-class SATA disk drives are coming along just as data centers are feeling the squeeze to store more data while conserving rack space, floor space and energy. "The array vendors are asking for bigger capacity drives," says Steege. A 750GB drive requires no more power than a 500GB drive. A 1TB drive will deliver 50% more capacity per watt than existing drives using the same enclosure.
Although extremely large drives present challenges in terms of RAID rebuilding time, storage
This was first published in December 2006