Re: Grub menu/MBR modifications

[lukshuntim]

On Tuesday, June 02, 2015 03:02 AM, Andrei Borzenkov wrote:
> В Mon, 1 Jun 2015 19:44:04 +0200
> Sverker Albatross <address@hidden> пишет:
>
> > I have an offline computer (I'm the only user) that's suddenly had its mbr
> > changed. I had a 10 s timeout, who suddenly has disappeared.  By removing
> > one older kernel package the timeout is there again. Can anyone explain
> > what's going on? It's a stripped kubuntu 12.04, offline/unupdated/wifi
> > disabled since 6 months back.
> >
> > Would anyone like to explain how/where/when the grub timeout is written?
>
> Some distributions disable timeout if one-time boot menu entry is set
> (grub-reboot); and in some cases grub cannot reset it during boot.
> Removing kernel likely triggers bootloader reconfiguration which /may/
> rewrite grubenv.
>
> There is not really enough information to make a guess.

Hi,

In ubuntu, there's a configuration file /etc/default/grub that sets the 
GRUB_TIMEOUT value. Installing/removing a kernel will run update-grub 
which reads it and create /boot/grub/grub.cfg. You can also run 
update-grub manually if you change it.

Hope this helps,
ST
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