ZFS raidz and 4k sector disks

Andriy Gapon avg at icyb.net.ua
Fri Apr 9 12:14:42 UTC 2010

on 09/04/2010 14:14 Alexey Tarasov said the following:
> Hello.
> I see considerably increased performance when creating over gnop -S 4096 virtual disk. Even when I create zpool over raw disks the performance is very bad and concurent writes stalls. When using gnop, zfs works VERY fast!
> Btw, here is another discussion, may be there is a bug in a mav@ commit, because he has added support for >512 sector size:
> http://lists.freebsd.org/pipermail/freebsd-current/2010-April/016495.html

Looks like I was wrong:
         * Determine the device's minimum transfer size.
        *ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1;

This is in vdev_geom_open and SPA_MINBLOCKSIZE is 512.

Andriy Gapon

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