Server product kernel requirements

[Josh Boyer]

On Thu, Oct 31, 2013 at 8:36 AM, Prarit Bhargava <prarit at redhat.com> wrote:
>
>
> On 10/30/2013 07:32 PM, Josh Boyer wrote:
>> On Wed, Oct 30, 2013 at 7:25 PM, Prarit Bhargava <prarit at redhat.com> wrote:
>>> On 10/30/2013 02:10 PM, Simo Sorce wrote:
>>>> On Wed, 2013-10-30 at 10:51 -0700, David Strauss wrote:
>>>>> On Wed, Oct 30, 2013 at 10:09 AM, Josh Boyer <jwboyer at fedoraproject.org> wrote:
>>>>>> Massive 4096 multi-cored CPU machines with terabytes of DRAM and
>>>>>> petabytes of storage, or more commodity style hardware used in
>>>>>> heterogeneous environments, etc.
>>>>>
>>>>> The latter. We'd want a separate HPC group for 512+ core machines.
>>>>
>>>> Or simply, sites so big can care for their own kernel builds most
>>>> probably, or seek for commercial support.
>>>
>>> Why limit it so low?  If we're thinking about going big, well, GO BIG.
>>>
>>> Users of Fedora want to support these systems out-of-the-box so they can get an
>>> idea if their systems work.  Stopping at 512 just seems too low these days.
>>>
>>> We're talking about saving a very small amount of memory by not going to 4096 ..
>>
>> Remind me how much again?  IIRC, it was around 2MB additional runtime
>> overhead to set MAX_CPUS to that, right?  That's very small on
>> servers, not so small on cloud.
>
> Right, I think that was about it... it may be a little less than that.  I
> wonder, however, how many people are actually using a bleeding-edge fedora
> kernel for memory-critical cloud purposes?  I have a feeling that it's in the
> same order of magnitude of people booting fedora on systems with greater than
> 512 cpus.

Well, that's why we're talking about this again.  With the 3 product
push Fedora is doing, we _want_ people using Fedora in the cloud and
on desktops (workstation) and on servers.  So I'm asking all 3 of
those products what their target use cases are.

(As for memory-critical cloud... I have no idea what that is to be
honest.  All I hear from the cloud people is "smaller is better".
Mostly that's image size, not memory overhead but I can imagine they
want that limited as well.)

josh