SOLVED How to force FreeNAS to use 4K sectors

[Brezlord]

I have a vdev made up of 6 4TB WD Red WD40EFRX drives that have a sector size of logical 512 physical 4096. I'm going to destroy the vdev and create a new one with 8 x 4TB drives all of the same type. How do i force 4K sector size? When I run zdb | grep ashift I get ashift: 9. There is no option in the GUI and it seams that FreeNAS 11 default is 512.

Can I run sysctl vfs.zfs.min_auto_ashift=12 to make ashift=12 the default for the system?

I have attached a little info from Western Digital on advanced format technology

root@nas1:~ # camcontrol identify da2
pass3: <WDC WD40EFRX-68WT0N0 82.00A82> ACS-2 ATA SATA 3.x device
pass3: 600.000MB/s transfers, Command Queueing Enabled

protocol ATA/ATAPI-9 SATA 3.x
device model WDC WD40EFRX-68WT0N0
firmware revision 82.00A82
serial number WD-WCC4E5LJ0FKN
WWN 50014ee262e580c9
cylinders 16383
heads 16
sectors/track 63
sector size logical 512, physical 4096, offset 0
LBA supported 268435455 sectors
LBA48 supported 7814037168 sectors
PIO supported PIO4
DMA supported WDMA2 UDMA6
media RPM 5400

 

[MrToddsFriends]

When I run zdb | grep ashift I get ashift: 9. There is no option in the GUI and it seams that FreeNAS 11 default is 512.

What is the output of zdb -U /data/zfs/zpool.cache | grep ashift? While zdb shows only the boot pool, zdb -U /data/zfs/zpool.cache shows all pools except the boot pool.

 

[Brezlord]

Hi Mr T,

Thanks for the cmd. I appears that the pool is indeed 4K.

root@nas1:~ # zdb -U /data/zfs/zpool.cache | grep ashift
ashift: 12
ashift: 12

 

[SweetAndLow]

Ashift 12 is the default no need to do anything special.