[OmniOS-discuss] 4kn or 512e with ashift=12

[Fred Liu]

> -----Original Message-----
> From: OmniOS-discuss [mailto:omnios-discuss-bounces at lists.omniti.com] On
> Behalf Of Jim Klimov
> Sent: 星期二, 三月 22, 2016 2:11
> To: Hanno Hirschberger; omnios-discuss at lists.omniti.com
> Subject: Re: [OmniOS-discuss] 4kn or 512e with ashift=12
> 
> 21 марта 2016 г. 10:02:03 CET, Hanno Hirschberger
> <hannohirschberger at googlemail.com> пишет:
> >On 21.03.2016 08:00, Fred Liu wrote:
> >> So that means illumos can handle 512n and 4kn automatically and
> >properly?
> >
> >Not necessarily as far as I know. Sometime drives are emulating 512
> >blocks and don't properly tell the OS about that and Illumos ZFS is
> >aligning the drives with ashift=9 which leads to enormous performance
> >issues. Also forcing the system to handle drives with a specific sector
> >
> >size with the sd.conf doesn't turn out to be reliable in some cases (at
> >
> >least on my workstations). Here's what I do to ensure ashift=12 values:
> >
> >Reboot the system with a Linux live disk of your choice and install ZoL
> >
> >in the live session. Then create the ZFS pool, export it and reboot the
> >
> >machine. OmniOS / Illumos can import the new pool without problems and
> >the ashift value is correctly set. There was a fixed zpool binary
> >(Solaris 11 binary) flying around the internet which can handle the "-o
> >
> >shift=12" parameter and works with OmniOS but unfortunately I can't
> >find it again right now. This would make the reboot into a live session
> >obsolete.
> >
> >Does anyone know if the "ashift" parameter will be implemented in the
> >OmniOS / Illumos zpool binary in the near future?
> >
> >Best regards
> >
> >Hanno
> >_______________________________________________
> >OmniOS-discuss mailing list
> >OmniOS-discuss at lists.omniti.com
> >http://lists.omniti.com/mailman/listinfo/omnios-discuss
> 
> Adding the ashift argument to zpool was discussed every few years and so far
> was always deemed not enterprisey enough for the Solaris heritage, so the
> setup to tweak sd driver reports and properly rely on that layer was pushed
> instead.
> 
> That said, the old tweaked binary came with a blog post detailing the source
> changes; you're welcome to try a d port and rti it (I'd say there is enough user
> demand to back the non-enterprisey fix to be on par with other OpenZFS
> siblings). At worst, you can publish the modernized binary as the original
> blogger did ;)

Is the post/source still accessible?


Thanks.

Fred