On 8/15/07, Gus Wirth <[EMAIL PROTECTED]> wrote: > Gregory K. Ruiz-Ade wrote: > > briefly: > > > > SCSI drives tend to be "enterprise" class devices. > [snip] > > To add some more information to an excellent summary, in the realm of > Non-Recoverable Error Rates (NRER, a measure of how often the drive gets > it wrong while reading data), enterprise class SCSI drives are at least > an order of magnitude better than most anything else out there. Back to > my previous examples, the Seagate ST3146854LC SCSI drive has a NRER of 1 > in 10^15, while the Western Digital WD1600YS (Enterprise level server > drive ) has a NRER of 1 in 10^14. The WD Raptor line claims 1 in 10^15. > > Gus
I have to wonder in a large storage system if the money is better spent on SCSI or on more disks intelligently arrayed. Given the huge differential in price between SCSI systems and ATA/SATA then I would need to see a serious engineering economic study to know which way wass better (including of course differntial costs of support.) There are I believe sufficient reasons not to discount immediately large clusters of low cost disks. Color me skeptical. I have _not_ done my homework but a quick scan of Google's studies suggests that the conventional wisdom about hard disks may be wrong. Those of you for whom this matters (not me) may well want to dig deeper into this. I am curious as to what your second opinions will be. See Google released a fascinating research paper titled Failure Trends in a Large Disk Drive Population (pdf) at this years File and Storage Technologies (FAST '07) conference. Google collected data on a population of 100,000 disk drives, analyzed it, and wrote it up for our delectation. http://labs.google.com/papers/disk_failures.pdf and discussion here http://storagemojo.com/?p=378 BobLQ -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
