I think that's a linux message. I've seen this before when output starts 
getting redirected to the serial port (or ipmi/iDRAC/iLO virtual serial 
port). Maybe check if there is some type of console redirection set up 
in the BIOS? It seems to me that when redirection is set up, the BIOS 
itself and GRUB can output to both serial and regular console; once the 
kernel boots, messages only go to one or the other.

The "hang" (or rather change in output) doesn't have anything to do with 
the EDD message itself - it just happens that this is the last message 
printed during that particular phase of booting.

G.

On 2/17/2017 10:33 AM, Konstantin Olchanski wrote:
> On Thu, Feb 16, 2017 at 10:07:55PM -0600, ~Stack~ wrote:
>> I have a bunch of new SuperMicro servers. Installed 7.3 on it. Reboot and it hangs at:
>> "Probing EDD (edd=off to disable)...ok"
>
> That's a BIOS message, not a linux or grub message, yes?
>
> (I do not see any EDD messages in the linux log files)
>
> Anyhow, *which* SuperMicro servers? (so I do not buy the same)
>
>> However, if I let it sit long enough it will boot (once one sat for an
>> hour before it continued on, most of the time it is closer to 30-40
>> minutes).
>
> The SuperMicro mobo/bios is notorious for slow booting, takes a good few minutes
> from powerup to grub menu. But 30 min is extreme, yes.
>
>> If I boot into rescue kernel, it instantly boots. Every time. This is so
>> puzzling to me.
>
> How do you mean? The "EDD" message is before grub menu or after grub menu?

-- 
Graham Allan
Minnesota Supercomputing Institute - [log in to unmask]