svn commit: r304142 - head/usr.sbin/bsdinstall/partedit

[Nathan Whitehorn]

On 08/18/16 05:56, Allan Jude wrote:
> On 08/18/16 05:50 AM, Dag-Erling Smørgrav wrote:
>> Nathan Whitehorn <nwhitehorn at freebsd.org> writes:
>>> OK. In which configurations? My Dell servers, for instance, don't do
>>> this. How are they set up? What drivers are being used? Is this
>>> something that affects passthrough disks, RAIDs, disk images?
>> Most LSI MegaRAID controllers don't have real passthrough, only JBOD.
>> You can query the drive with "camcontrol identify passX", but the
>> controller does not report a stripe size for the volume (mfidY).
>>
>>> The point is that *if the reported stripe size is wrong*, more things
>>> than partition alignment in the installer will suffer for it.
>> It's not wrong, it's non-existent, and I'm getting really tired of
>> repeating myself.
>>
>>> Fixing the installer with a bandaid in the run-up to a release is
>>> fine, but *we need to fix the underlying problem*.
>> We can't, because hardware sucks, and I'm getting really tired of
>> repeating myself.
>>
>> DES
>>
> Which makes more sense:
>
> A) If stripesize == 0, use some sane value like 4096
>
> B) Some other combination that uses the reported stripe size, unless it
> is 0, in which case it uses 4096 (or some other value controlled by a
> different new sysctl)
>
> C) create kern.geom.min_stripe_size with a default of 512, but users can
> set 4096 if they use only 4k devices. (doesn't really solve the problem
> for the installer)

I think "B" does what we want here best, but any of these approaches 
would work well.
-Nathan