Syslinux - Nov 2013 - IPMI serial over lan disconnects seem to trigger extlinux reboots

Hi,

On Tue, Nov 12, 2013 at 01:41:29PM -0800, H. Peter Anvin
wrote:
> On 11/12/2013 01:22 PM, Andrew J. Schorr wrote:
> > I am using 4.05 because that's what's packaged in the latest
Fedora
> > release (Fedora 19 in my case).  I wonder why they are using such an
> > old version.  I will take a look at how difficult it would be to build
> > the latest version on Fedora.
FYI, it is not so easy to package for Fedora.  I see there is an open
bug to get this upgraded:

   https://bugzilla.redhat.com/show_bug.cgi?id=869540
> One possibility is that either the PXE stack or the BMC uses memory that
> it shouldn't.  Try setting a mem= option with less memory than you
> actually have and see if that changes things.
That's an interesting idea.  I may give that a try.  Just to be clear,
are you talking here about the kernel "mem=" boot parameter, as
documented
in kernel-parameters.txt?

        mem=nn[KMG]     [KNL,BOOT] Force usage of a specific amount of memory
                        Amount of memory to be used when the kernel is not able
                        to see the whole system memory or for test.
                        [X86] Work as limiting max address. Use together
                        with memmap= to avoid physical address space collisions.
                        Without memmap= PCI devices could be placed at addresses
                        belonging to unused RAM.

I wonder if that has negative implications for subsequent system performance...

I also think I had the same troubles booting into memtest, so it may be
a more general problem.

Probably the best solution would be to replace these machines with newer
ones, but that will be painful since they are in the field.

Thanks,
Andy

Hi,

For whatever it's worth, the same problem seems to occur with Fedora
19's
grub2 2.00 package.  Only the old grub was OK.  Sigh.  I guess the BMC
implementation on this motherboard is buggy.

Regards,
Andy

On Tue, Nov 12, 2013 at 5:20 PM, Andrew J. Schorr
<aschorr at telemetry-investments.com> wrote:
> Hi,
>
> On Tue, Nov 12, 2013 at 01:41:29PM -0800, H. Peter Anvin wrote:
>> On 11/12/2013 01:22 PM, Andrew J. Schorr wrote:
>> > I am using 4.05 because that's what's packaged in the
latest Fedora
>> > release (Fedora 19 in my case).  I wonder why they are using such
an
>> > old version.  I will take a look at how difficult it would be to
build
>> > the latest version on Fedora.
>
> FYI, it is not so easy to package for Fedora.  I see there is an open
> bug to get this upgraded:
>
>    https://bugzilla.redhat.com/show_bug.cgi?id=869540
>
>> One possibility is that either the PXE stack or the BMC uses memory
that
>> it shouldn't.  Try setting a mem= option with less memory than you
>> actually have and see if that changes things.
>
> That's an interesting idea.  I may give that a try.  Just to be clear,
> are you talking here about the kernel "mem=" boot parameter, as
documented
> in kernel-parameters.txt?
Yes.  If the system has about 8192MiB RAM, I'd start by shaving it off
in about 16MiB increments or perhaps take a binary search tree pattern
approach.
> I wonder if that has negative implications for subsequent system
performance...
Judicious use of that parameter should have minimal impact.  You are
right to think that it will make said RAM unavailable later but it
also affects where Syslinux loads the kernel/initrd.
> I also think I had the same troubles booting into memtest, so it may be
> a more general problem.
>
> Probably the best solution would be to replace these machines with newer
> ones, but that will be painful since they are in the field.
At least there are possibilities remaining in the interim.

-- 
-Gene

On 11/14/2013 03:39 AM, Gene Cumm wrote:
> On Tue, Nov 12, 2013 at 5:20 PM, Andrew J. Schorr
> <aschorr at telemetry-investments.com> wrote:
>> Hi,
>>
>> On Tue, Nov 12, 2013 at 01:41:29PM -0800, H. Peter Anvin wrote:
>>> On 11/12/2013 01:22 PM, Andrew J. Schorr wrote:
>>>> I am using 4.05 because that's what's packaged in the
latest Fedora
>>>> release (Fedora 19 in my case).  I wonder why they are using
such an
>>>> old version.  I will take a look at how difficult it would be
to build
>>>> the latest version on Fedora.
>>
>> FYI, it is not so easy to package for Fedora.  I see there is an open
>> bug to get this upgraded:
>>
>>    https://bugzilla.redhat.com/show_bug.cgi?id=869540
>>
>>> One possibility is that either the PXE stack or the BMC uses memory
that
>>> it shouldn't.  Try setting a mem= option with less memory than
you
>>> actually have and see if that changes things.
>>
>> That's an interesting idea.  I may give that a try.  Just to be
clear,
>> are you talking here about the kernel "mem=" boot parameter,
as documented
>> in kernel-parameters.txt?
> 
> Yes.  If the system has about 8192MiB RAM, I'd start by shaving it off
> in about 16MiB increments or perhaps take a binary search tree pattern
> approach.
> 
Actually, start by dropping it down to mem=2G, and move downward from there.
>> I wonder if that has negative implications for subsequent system
performance...
It will, but it would be useful as a diagnostic tool.

	-hpa