[OpenIndiana-discuss] Very slow write performance on a 3 disk raidz1-0 zpool

[Julius Roberts]

On 24 August 2012 18:02, Bryan Iotti <ironsides.medvet at gmail.com> wrote:
> Are these Advanced Format Drives (4k sectors) already?

I don't know?

> My own WD Caviar Green 2TB sucked bad before I recreated a pool on it with
> the modified zpool-12 command.

This pool was created in 2008(?) using zfs v10 on solaris express
developer edition, and was recently upgraded to v5000 or whatever it
is that comes with OIa5.

> You could run:
> # zdb <pool name> | grep ashift
>
> And see what value you get. If you have 9, the pool is structured for 512
> byte sectors and a 4k drive could suffer a performance loss. For a 4k
> drive, the ASHIFT value should be 12.

twsadmin at darling:~/mdbackup/today$ sudo zdb Backups | grep ashift
Password:
                ashift: 9
                ashift: 9
^C

What does this mean exactly and what is the expected performance loss
in this situation?

-- 
Kind regards, Jules

<golgy> whats so wrong with plumb?
<hoolio> nothing, in itself.  it's just for me, knowing what it means
infers i cannot any longer pretend to not be a complete square when it
comes to computers
<Gryphon> I don't know that knowing anything about plumb turns you
into a nerd, but this conversation already has
<hoolio> are you calling me nerdy?
<checkers> hoolio: you know what initramfs means, AND does. You're
lost to the non-geek world already
<Gryphon> yes
<hoolio> hrm
<hoolio> goodbye cruel world.