ZFS and 4k sector drives

Wojciech Puchar wojtek at tensor.gdynia.pl
Mon Nov 15 19:24:04 UTC 2010

> work with ZFS raidz2 pools.  It seems that most of the 4k sector drives are 
> using emulation, and reporting 512 byte sectors to the OS instead of their 
> native 4k size.  I know someone who had an issue trying to insert one of 
> these drives into a running ZFS pool with other 512 byte sector drives with 
> bad results.

ZFS use 4k blocks. assuming it actually is like that and your zfs devices 
are whole devices or aligned partition, there should be no difference.

use camcontrol identify to check what your drive do

[root at somewhere ~]# camcontrol identify ada0
pass0: <SAMSUNG HD321KJ CP100-10> ATA-8 SATA 2.x device
pass0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes)

protocol              ATA/ATAPI-8 SATA 2.x
device model          SAMSUNG HD321KJ
firmware revision     CP100-10
serial number         S0MQJDQP610759
WWN                   5000f00db61759
cylinders             16383
heads                 16
sectors/track         63
sector size           logical 512, physical 512, offset 0
LBA supported         268435455 sectors
LBA48 supported       625142448 sectors
PIO supported         PIO4
DMA supported         WDMA2 UDMA6

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