On 10/25/2013 06:42 AM, NeilBrown wrote:

On Fri, 25 Oct 2013 11:51 +0300 Dag Nygren [off-list ref] wrote:

quoted

Hi all!

Just run into the standard problem by not having SCTERC enabled
for my drives due to a spelling mistake in my rc.local script
setting the parameters and started wondering:

- What if the md module automatically set this during assembly
of the RAID? - In the kernel module itself. It could always set it,
if the set failed we could spit out a kernel warning that the used
drive might not be the best as a RAID device. Would there be any ill
effects from this?
- And ditto for the device time-out.

This would definitely make md work a lot better for people. I have a
strange feeling that most don't know the parameter needs setting...

No strange feeling at all.  Most of my posts to this list are helping
people bitten by it.

I don't think it is appropriate for the kernel to automatically set such
things.  However it might be appropriate for mdadm to do it when assembling
or creating the array.

I'm happy to review and  possibly accept patches.

This is a wonderful idea, as it could possibly help people stuck on
older kernels.  I'll take a look at doing this myself.

Phil