On Thu, May 13, 2010 at 06:09:55PM +0200, Roy Sigurd Karlsbakk wrote: > 1. even though they're 5900, not 7200, benchmarks I've seen show they are > quite good
Minor correction, they are 5400rpm. Seagate makes some 5900rpm drives. The "green" drives have reasonable raw throughput rate, due to the extremely high platter density nowadays. however, due to their low spin speed, their average-access time is significantly slower than 7200rpm drives. For bulk archive data containing large files, this is less of a concern. Regarding slow reslivering times, in the absence of other disk activity, I think that should really be limited by the throughput rate, not the relatively slow random i/o performance...again assuming large files (and low fragmentation, which if the archive is write-and-never-delete is what i'd expect). One test i saw suggests 60MB/sec avg throughput on the 2TB drives. That works out to 9.25 hours to read the entire 2TB. At a conservative 50MB/sec it's 11 hours. This assumes that you have enough I/O bandwidth and CPU on the system to saturate all your disks. if there's other disk activity during a resilver, though, it turns into random i/o. Which is slow on these drives. danno -- Dan Pritts, Sr. Systems Engineer Internet2 office: +1-734-352-4953 | mobile: +1-734-834-7224 Visit our website: www.internet2.edu Follow us on Twitter: www.twitter.com/internet2 Become a Fan on Facebook: www.internet2.edu/facebook _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
