On Nov 26, 2010, at 20:09 , taemun wrote: > If you consider that for a 4KB internal drive, with a 512B external > interface, a request for a 512B write will result in the drive reading 4KB, > modifying it (putting the new 512B in) and then writing the 4KB out again. > This is terrible from a latency perspective. I recall seeing 20 IOPS on a WD > EARS 2TB drive (ie, 50ms latency for random 512B writes).
Agreed. However, if you look at this MS KB article: http://support.microsoft.com/kb/982018/en-us , Windows 7 (even with SP1) has no support for 4K-sector drives. Obviously, we're dealing with ZFS and Solaris/BSD here, but what I'm getting at is, which 4K sector drives offer a jumper or other method to completely disable any form of emulation and appear to the host OS as a 4K-sector drive? I believe the Barracuda LPs (the 5900rpm) disks can do this, but I'm not sure about the others like the F4s. I believe you earlier said you were using F4s (the HD204UIs) and the 5900rpm Seagates; can you explicate further about these drives and their emulation (or lack thereof), I'd appreciate it! --khd _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
