Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 12 Jan 2017 23:57:45 +0100
From:      Stefan Bethke <stb@lassitu.de>
To:        freebsd-stable <freebsd-stable@freebsd.org>
Subject:   Re: zpool asize problem on 11.0
Message-ID:  <F4074A09-D872-44A6-9A9B-492E51C4CE15@lassitu.de>
In-Reply-To: <01B0C796-CB6D-412D-AB93-05836906BC89@lassitu.de>
References:  <01B0C796-CB6D-412D-AB93-05836906BC89@lassitu.de>

next in thread | previous in thread | raw e-mail | index | archive | help

> Am 12.01.2017 um 23:29 schrieb Stefan Bethke <stb@lassitu.de>:
>=20
> I=E2=80=99ve just created two pools on a freshly partitioned disk, =
using 11.0 amd64, and the shift appears to be 9:
>=20
> # zpool status -v host
>  pool: host
> state: ONLINE
> status: One or more devices are configured to use a non-native block =
size.
> 	Expect reduced performance.
> action: Replace affected devices with devices that support the
> 	configured block size, or migrate data to a properly configured
> 	pool.
>  scan: none requested
> config:
>=20
> 	NAME         STATE     READ WRITE CKSUM
> 	host         ONLINE       0     0     0
> 	  gpt/host0  ONLINE       0     0     0  block size: 512B =
configured, 4096B native
>=20
> errors: No known data errors
>=20
> # zdb host | grep ashift
>                ashift: 9
>                ashift: 9
>=20
> But:
> # sysctl vfs.zfs.min_auto_ashift
> vfs.zfs.min_auto_ashift: 12
>=20
> Of course, I=E2=80=99ve noticed this only after restoring all the =
backups, and getting ready to put the box back into production.
>=20
> Is this expected behaviour?  I guess there=E2=80=99s no simple fix, =
and I have to start over from scratch?

I had falsely assumed that vfs.zfs.min_auto_ashift would be 12 in all =
circumstances.  It appears when running FreeBSD 11.0p2 in VirtualBox, it =
can be 9.  And my target disk was attached to the host and mapped into =
the VM as a =E2=80=9Enative disk image=E2=80=9C, but the 4k native =
sector size apparently got lost in that abstraction.

The output above is with the disk installed in the target system with a =
native AHCI connection, and the system booted from that disk.

I=E2=80=99ve certainly learned to double check the ashift property on =
creating pools.


Stefan

--=20
Stefan Bethke <stb@lassitu.de>   Fon +49 151 14070811







Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?F4074A09-D872-44A6-9A9B-492E51C4CE15>