I find myself in another nice catch 22.
Some time last week, I updated with yum (after several weeks of not updating) and, for some reason, I was able to reboot that day, but the next day attempting to boot Fedora resulted in a kernel panic.
Looking things up, I see I'm not the only one with a panicking kernel.
So, I got to work to clear the crudded kernel out of the way.
Took me a while of looking around the web to rediscover the incantation to get to rescue mode with an install CD: "linux rescue" at the second stage boot prompt.
Then I booted to rescue mode. I was thinking along the lines of, even though I don't get a grub menu like on x86, I should be able to change the configuration file to default to the previous kernel.
Is the usual approach to that to use ybin? (And it looks like, with all the strange parameters, and the success rate I'm having today with arcane command parameters, it would likely take several tries to get it right.)
Isn't there an easier way to do this?
I tried passing the kernel name of the previous kernel in at the second stage prompt, but, even though I figured out (again) the arcane open firmware syntax to point to the kernel:
hd:<drive>,/vmlinuz-<version>.ppc
(Since the boot volume is separate, the path to the kernel is empty.)
it tells me that I should try passing in the init= parameter. I tried several permutations of what I thought was the probable syntax,
boot: hd:3,/vmlinuz-2.6.29.5-191.fc11.ppc init=/ initrd-2.6.29.5-191.fc11.ppc.img
and such, but all of them failed to execute, suggested specifying init= and left me at 180 seconds to reboot.
So I'm having a hard time with things today. Can someone put me out of my misery?
Joel Rees
On 09/26/2009 08:27 PM, Joel Rees wrote:
I find myself in another nice catch 22.
...
So I'm having a hard time with things today. Can someone put me out of my misery?
Yeah, mate, take that .22 above and...
No seriously: Without having a ppc machine, I imagine that you can hit escape or any key during boot, so that you get the boot loader's option menu, and move the cursor to the previous kernel entry, hit enter...
As long as the older working kernel is still installed, it should be enough to yum remove kernel.specific.bad.version, and the rpm should take care of setting the previous versions item as the one to boot.
DaveT.
On Sat, Sep 26, 2009 at 5:05 PM, David Timms dtimms@iinet.net.au wrote:
On 09/26/2009 08:27 PM, Joel Rees wrote:
I find myself in another nice catch 22.
...
So I'm having a hard time with things today. Can someone put me out of my misery?
Yeah, mate, take that .22 above and...
No seriously: Without having a ppc machine, I imagine that you can hit escape or any key during boot, so that you get the boot loader's option menu, and move the cursor to the previous kernel entry, hit enter...
As long as the older working kernel is still installed, it should be enough to yum remove kernel.specific.bad.version, and the rpm should take care of setting the previous versions item as the one to boot.
For Fedora 11 the default maximum number of kernels for yum to keep installed is set at 3. The two prior kernels plus the broken one should be available.
Now, if you really care about what is happening to your system during boot I recommend that you edit /boot/grub/grub.conf (alias menu.lst). Comment out the "hiddenmenu" line (put a '#' in front of the 'h'). This will allow the other installed kernels and/OS's to be displayed as selectable boot options. (Increase the number in the "timeout=" line if you want more time at making a selection.) Delete "quiet" and "rhgb" from all the kernel stanzas if you want to see additonal details and status of drivers and services during the boot process.
On 27 Sep 2009 10:05:04 +1000, David Timms wrote,
On 09/26/2009 08:27 PM, Joel Rees wrote:
I find myself in another nice catch 22. ... So I'm having a hard time with things today. Can someone put me out of my misery? Yeah, mate, take that .22 above and...
Thanks for the sympathy. ;-/
No seriously: Without having a ppc machine, I imagine that you can hit escape or any key during boot, so that you get the boot loader's option menu, and move the cursor to the previous kernel entry, hit enter...
Yeah, you'd think. Open Firmware doesn't seem to be as tame as BIOS, however. It should allow typing the kernel name in at the boot prompt, but I couldn't get that to go, either. It would take the name of the down-level kernel, but it couldn't find the init. I tried specifying that with "init=", but it wouldn't take the path any way I could think of, without or without the drive spec, etc.
As long as the older working kernel is still installed, it should be enough to yum remove kernel.specific.bad.version, and the rpm should take care of setting the previous versions item as the one to boot.
Let me tell you what I eventually did:
Inserted the netinstall CD and hit the power switch, held down the C key as one does on Macs.
At the Fedora installer's boot prompt,
boot: linux rescue
After setting the language and keyboard and letting it start the network, it asks whether to try to mount the file system read only under /mnt/sysimage, and I took that option.
Once it gave me a shell, I used mount with no parameters to get a look at what was where, then started umount-ing the volumes in order and then mounting them, so that they were mounted read-write. But I wasn't sure what to do with some of the more esoteric volumes.
But it still wouldn't let me run yum under chroot /mnt/sysimage .
Couldn't find the name server for some reason, and /etc was under /, which was still ro, and I really didn't want to umount everything again so I could mount / rw and edit resolv.conf to see if that would point the box back to the name server. (Got to put /etc in it's own partition next time, I guess. Or, if I had had my crystal ball out, I'd have set the network by hand instead of letting DHCP handle it.)
So I gave that up and just mv-ed the offending kernel out of the way and ln-ed the previous kernel, config, initrd, and System.map to the old kernel's name.
It boots up, and yum runs, but I'm worried about the naming games. Unfortunately, when I yum info the kernel, it looks like they haven't fixed the kernel yet after all, so I guess I'll yum remove the bad kernel. After filing a bug on it.
Then I'd better practice using yaboot and, what was it? ybin? (And bash, too. Double checking those long version strings in the middle of file names is not something you want to do under pressure or late at night.)
Thanks for the comments. I'm wondering if I'm the only PPC Fedora user left on the planet.
Joel Rees
Kam Leo wrote:
On Sat, Sep 26, 2009 at 5:05 PM, David Timms dtimms@iinet.net.au wrote:
On 09/26/2009 08:27 PM, Joel Rees wrote:
I find myself in another nice catch 22.
...
So I'm having a hard time with things today. Can someone put me out of my misery?
Yeah, mate, take that .22 above and...
No seriously: Without having a ppc machine, I imagine that you can hit escape or any key during boot, so that you get the boot loader's option menu, and move the cursor to the previous kernel entry, hit enter...
As long as the older working kernel is still installed, it should be enough to yum remove kernel.specific.bad.version, and the rpm should take care of setting the previous versions item as the one to boot.
And after booting the old kernel, "yum erase" will remove the offending new one.
For Fedora 11 the default maximum number of kernels for yum to keep installed is set at 3. The two prior kernels plus the broken one should be available.
Now, if you really care about what is happening to your system during boot I recommend that you edit /boot/grub/grub.conf (alias menu.lst). Comment out the "hiddenmenu" line (put a '#' in front of the 'h'). This will allow the other installed kernels and/OS's to be displayed as selectable boot options. (Increase the number in the "timeout=" line if you want more time at making a selection.) Delete "quiet" and "rhgb" from all the kernel stanzas if you want to see additonal details and status of drivers and services during the boot process.
About the only thing I think is really needed is the timeout increase, since once you get the menu up by hitting a key you can do the rest. I also want more than 3 old kernels, I'd increase that one as well. Deleting rhgb is a good idea with some video hardware, for sure, unless I have problems quiet is fine, I just want to know if there's a problem.
-
Bill Davidsen -
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