ZFS secondarycache on SSD problem on r255173

[Justin T. Gibbs]

On Sep 17, 2013, at 4:53 PM, Steven Hartland <killing at multiplay.co.uk> wrote:

> ----- Original Message ----- From: "Justin T. Gibbs" <gibbs at freebsd.org>
> 
> 
>> Sorry for being slow to chime in on this thread.  I live in Boulder, CO and we've had a bit of rain. :-)
> 
> Hope all is well your side, everyone safe and sound if may be little wetter than usual.

I have been very fortunate.

>> As Steven pointed out, the warning is benign, but does show that the code I committed to
>> -current is not optimizing the allocation size for L2ARC devices.  The fix for this is to find
>> the best place during pool creation/load/import to call vdev_ashift_optimize() on L2ARC
>> devices.  I will look into this tomorrow, but feel free to suggest a good spot if you look at it
>> before I can.
> 
> The attached patch fixes this for me, not sure if its ideal place for it and consideration may be
> needed in combination with persistent l2arc.

Persistent l2arc will require storing and checking the ashift recorded in the label so bugs and
or quirk table changes don't confuse the system.  But for now, with no persistent l2arc support
in the tree, I think your placement is fine.  I've submitted a request to RE so I can put your fix into head.

--
Justin