Grub2 - keyboardless boot problems

[Neil Cooper]

Hi all,

I have a (keyboardless) mythtv server running 64 bit ubuntu 10.4.

When the system is inactive, mythtv sets the bios wakeup to power up the box in 
time to record the next tv show scheduled for recording, then shuts itself down.

Generally this works very well, but once in a while (like once in maybe 500 
boots) grub fails with an error message saying it was unable to find a file 
(annoyingly not mentioning which one).

The box is running a single drive, so the problem can't be caused by multi-disk 
issues such as a delay for other drives or raid arrays to come up.

As such cases are rare, I get by with manually power-cycling the box whenever 
it happens, however whats REALLY annoying is that even though grub2 has been 
configured to automatically boot Linux, when it comes up after such a fault it 
just goes to the boot menu, which requires a keyboard to use. I now have to go 
find a keyboard and plug it in just to manually select linux even though it 
should be set to automatically boot. After a successful boot, subsequent boots 
automatically revert to expected menuless behaviour.

My questions are:
1) Why very occasionally does grub2 not find a file? The drive must be 
up/readable otherwise grub2 itself wouldn't have gotten loaded.

2) How do I set it so that on the next reboot after a boot failure, grub2 just 
tries to load Linux again, instead of bringing a keyboard-driven boot menu?

Thanks Guys,
Neil Cooper