FluKex 1 Posted April 16, 2007 Share Posted April 16, 2007 So, over the past while i have been working on getting a new kernel working on my system. The problem i was having is that the newer kernels i use are not loading the sata modules properly from the initrd images. When trying to fix this i would run into the scnenario whereas, i reboot using the new kernel and if it kernel panics, i then have to file a ticket with my hosting provider to reboot the system and select the old kernel. I have now found 2 ways around this that might be useful for anyone who does a lot of kernel testing. 1.) Booting once-only - (same as lilo -R) In reference to http://www.gnu.org/software/grub/manual/gr...g-once_002donly in grub.conf, add the following line to the beginning. default saved If for example your grub.conf looks like the one i have below. This boots into the 2.6.20-1.2944 by default. default=0 timeout=5 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu title Fedora Core (2.6.20-1.2944.fc6) root (hd0,0) kernel /vmlinuz-2.6.20-1.2944.fc6 ro root=LABEL=/ acpi=off initrd /initrd-2.6.20-1.2944.fc6.img title Fedora Core (2.6.20-FluKex.com) root (hd0,0) kernel /vmlinuz-2.6.20-FluKex.com ro root=LABEL=/ acpi=off initrd /initrd-2.6.20-FluKex.com.img If you want to have it so that 2.6.20-FluKex.com boots on next boot, run the following command from the console before rebooting. echo "savedefault --default=1 --once" | grub --batch then reboot Now, if you have a kernel that panics and need it to reboot if it panics. change your config and add the panic=# (# being seconds before auto reboot) to the kernel line. Example file below default=0 timeout=5 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu title Fedora Core (2.6.20-1.2944.fc6) root (hd0,0) kernel /vmlinuz-2.6.20-1.2944.fc6 ro root=LABEL=/ acpi=off panic=5 initrd /initrd-2.6.20-1.2944.fc6.img title Fedora Core (2.6.20-FluKex.com) root (hd0,0) kernel /vmlinuz-2.6.20-FluKex.com ro root=LABEL=/ acpi=off panic=5 initrd /initrd-2.6.20-FluKex.com.img so the order of operations on this are as follows. 1.) Add new kernel to grub.conf 2.) set default=# in grub.conf to the failsafe kernel (the one you want it to try if the other fails) 3.) run the following: echo "savedefault --default=1 --once" | grub --batch 4.) reboot This will try the flukex.com kernel, and if it panics, it will reboot and use the normal default kernel. BLAM works for me. Quote Link to post Share on other sites
FluKex 1 Posted April 16, 2007 Author Share Posted April 16, 2007 btw, it looks as though fedora core 6 has removed the "grub-set-default" option and does not use the /boot/grub/default file. There are a few different methods on how to do a "once only" boot with grub, but unforuntately fedora can only do the 1 i posted above. Quote Link to post Share on other sites
Randall 0 Posted April 16, 2007 Share Posted April 16, 2007 Nice work. Quote Link to post Share on other sites
anyweb 490 Posted April 16, 2007 Share Posted April 16, 2007 agreed, thanks flukex for posting this cheers anyweb Quote Link to post Share on other sites
znx 24 Posted April 17, 2007 Share Posted April 17, 2007 Nice Quote Link to post Share on other sites
xDamox 10 Posted April 17, 2007 Share Posted April 17, 2007 Yea Nice post Quote Link to post Share on other sites
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