Kernel upgrade crashed my ZenMini!

[wharfhouse]

Hi all,

Think I've tried to be a bit too clever... I attempted to upgrade to the current kernel (2.6.38.2.bfs) from the one in ZenMini 2010 (2.6.33.7.bfs) thinking it was the right thing to do, and also thinking that I would have the choice of two kernels to boot into in Grub... but alas wrong on both counts!

I get stuff on the new default boot up saying that it's attempting to start the Xserver (several times by the looks of it) but fails.

I downloaded this kernel from Synaptic.  What's the best way out?  I've found out since that there's no need to upgrade kernels unless some new piece of hardware doesn't work which isn't the case with me 

Is there a way of getting back my old kernel using the liveCD to cut & paste the kernel somehow, or is it a reinstall of /root from the live CD?

They say the best way to learn is to make mistakes... except I've screwed up big time this time!

Thanks.

[Texstar]

I'm sorry but the information you have presented is not accurate. Installation of a kernel from Synaptic does not remove the previous kernel. It adds an additional entry into your grub menu.lst and you have the option of booting into the original kernel or the new kernel. The reason we do it that way is if there is a hardware conflict of some kind (very rare) with the new kernel you can always boot into the original. Also booting a new kernel for the very first time requires a few minutes to complete new video kernel driver build. If you leave it alone it will complete the process and take you to the desktop. This is a one time boot delay and further reboots will boot as normal speed. If you power off or reset your computer during this dkms kernel video driver update then try to boot into the new kernel, there is a chance your video will fail because you interrupted the building of the kernel video drivers. I'm not going to offer a solution other than reinstall because I feel the information presented here is somehow tainted.

[wharfhouse]

Hi Tex,

I'm sorry but what I said above is exactly what happened.  On first boot up after the synaptic install of the kernel, Grub just listed the same two options: boot into PCLOS or into safe mode... no other kernel options listed.  It then went into a black screen with an extending blue bar at the bottom going from dark blue to light blue then to white.  Text then scrolled down the screen before  going into the GUI... this is the point where it goes wrong (I'm working off memory here from another PC!): the zen mouse thingy rotates on a black screen (as normal) then the screen flashes several times then the error message about "tried to start the Xserver 3 times, I need to check my settings".  A window pops up (still on a black screen at this point... no desktop) showing my CORRECT video settings i.e. graphics card (NVidia MX2-400), resolution, monitor et al.  I press OK because it is and the cycle starts again!  At some point it drops me back to strange prompt I hadn't seen before which at least allows me to type in the terminate command and shut down properly.

There's no question of me not allowing the kernel time to rebuild the driver list, I never interrupted the process at any time.  So what do you reckon

You say the original kernel is still there, how can I access it? Through the Grub menu lst? Will the two kernels be in there to edit?  I can do that from a liveCD possibly?

Thanks Tex... and while I've got your attention, having been an MS user for m-a-n-y years, and tried several Linux distros, I think you have a superb OS here... the only problem is with plonkers like me in having to relearn how it all works!

[wedgetail]

wharfhouse
Sounds interesting, not quite a dead system. I think you have two options for a bit of fun.  

1.. If you are konsole junkie the strange prompt can be used for some command line work, such as:

Code: [Select]

[gert@localhost ~]$ ls /boot/
boot.backup.sda
config@
config-2.6.33.7-pclos6.bfs
gfxmenu*
grub/
initrd-2.6.33.7-pclos6.bfs.img
initrd.img@
kernel.h@
kernel.h-2.6.33.7-pclos6.bfs
memtest-4.10
message-graphic
System.map@
System.map-2.6.33.7-pclos6.bfs
us.klt
vmlinuz@
vmlinuz-2.6.33.7-pclos6.bfs
[gert@localhost ~]$ ^C
[gert@localhost ~]$

In your case if you have a new kernel you will see that there is doubling of entries?

2..
In case the thought of using command line makes you tremble then assuming you have a ZenMini LiveCD, boot that and go exploring you hard drive install and check the /boot content. You then have the comfort of Graphics interface.

3..
Is it a mission critical install that you have trouble with now? Do you need to rescue data first before embarking on a bit of adventure?  

At the moment I am not in ZenMini and my posts may show thing a bit different.

[Dragynn]

@Wharfhouse: I've had similar experiences with the new kernels, Nvidia drivers and intermittent crashes and failures to start X, also running Zen-mini. installing 2.6.38.4 completely killed sound on another machine. I'm rolling back all my installs to 2.6.33.7 and deleting all 2.6.38's. I've tested these on multiple machines now, and each one has caused some sort of malfunction.

[Neal ManBear]

Wharfhouse,
Rather than continue with the nvidia driver, switch to the vesa driver to log in to your desktop. Once there, open PCC and set up your nvidia driver. Reboot.

[wharfhouse]

Hi to all you Guys and thanks for your remarks... I'll take them in turn:

Wedgetail: not sure what you're suggesting here... should I type out the commands in #1 to see what happens? And NO, I'm a complete philistine with bash consoles... DOS is bad enough!

In #2 I did already look in my /boot directory for any clues, but then again I haven't a clue what I expected to see (bear with me here, I've still got my 'L' plates on with Linux!).

#3 no, my data is shared on a FAT32 partition completely separate to Linux, I put my Linux/home also on a separate partition so as not to loose my configurations and tweaks so if the worst comes to the worst I can re-install root from my liveCD.

Dragynn: sounds like you've been where I am now; so how do you "roll back" to the previous kernel from a crashed system which was what I asked Tex?

Neal: yeah that's what I thought, but how the hell do you do that when there's no option to boot into vesa mode?  I only see that on a liveCD and in fact that was one of the first things I learned about PCLOS when I was trying it out... wouldn't boot into the default till I found subsequently about the issues with NVidia cards and drivers!

Wow, the learning curves keep on coming... there's so much to know!

Thanks to all of you!

[johnmart]

Hi wharfhouse,
You can do Neal's advice by running XFdrake from command line.

open a konsole,
note: commands are case sensitive.

Login as root with your root password
XFdrake

from there you can choose the vesa graphics driver & continue with Neal's advice.
hth
John
oops. open the gnome console. 

[Neal ManBear]

A window pops up (still on a black screen at this point... no desktop) showing my CORRECT video settings i.e. graphics card (NVidia MX2-400), resolution, monitor et al. 

It is at this point that you should switch to the vesa driver.

[wedgetail]

wharfhouse

Just testing, you did not really tell me much, now I know about your ability in konsole.  First of all follow up on the other members suggestions.

However when you were looking in /boot you should see one or more similar items (not identical) to vmlinuz-2.6.33.7-pclos6.bfs telling you that you have kernel for each different set you see.

[wharfhouse]

Morning All!

Thanks for your replies and suggestions.  I'll try going into the vesa driver as soon as I have another go in the next day or two... bit tied up at the moment

Wedgetail... yes I did see several entries for vmlinux and other bits & pieces relating to these kernels... incidentally what does bfs stand for?  I did notice when I looked in Synaptic at kernels there were quite a lot of variations under the same kernel number i.e. their suffix.  I chose bfs because I thought it would be a safe bet as the installed one from the CD was a bfs!

Thanks to all

[wedgetail]

wharfhouse
I think it is looking promising for you, we will see.  When you run out of other options, then open konsole and do

Code: [Select]

[gert@localhost ~]$ ls /boot/

Post the result.

-bfs, well for us plodders just forget about the letters and use it. Something to do with kernel task scheduling, which we don't bother about.

You can also slip along and look here:

http://www.stackednotion.com/2010/06/04/what-are-bfs-and-cfs

[wharfhouse]

Hi All,

Managed to find a bit of time looking at my problem... not good

Neal I managed to go into vesa mode as suggested and I thought for a moment I was sorted.  Rebooted and... well... talk about Microsofts' BSOD, this was Linux "white screen of death"!  Tried this several times with no user interaction offered during the boot.  No response of any kind from the keyboard but just the zen mouse cursor operable!  OK, reboot into failsafe mode as sort of suggested by johnmart to get to a prompt... had to press the reset button to do this (which of course Linux doesn't particularly like).  The boot process just hung half way through and not because it was going through a file system check and repair (which what usually happens after pressing the reset without proper shut-down) because there was no HD activity for a long time.

I came to the conclusion that I'd stumbled into an unrecoverable situation here so I'm afraid it was a reformat and start again job
So, not exactly "solved" but a learnt lesson not to mess with kernels unless you know what you're doing   Shame because I thought part of the fun with Linux is you could experiment without getting too unstuck!

Anyway, thanks for all your help Guys and when I'm back where I was I'll continue to experiment with my transparent windows (post) which Neal again was helping me out... surely that's a safe bet? 

[Neal ManBear]

wharfhouse,
Some things to remember when you install a new kernel:
First: Upgrading your kernel is optional. If the kernel you are using works well for you, you can continue to use it.
Second:Do not uninstall the old kernel. It will remain as a boot entry that can be used as a fall back in case the newer kernel does not work well for you.
Third: If you go back to using the old kernel and choose to uninstall the new kernel, check in Synaptic history to see what, if anything, was uninstalled when you installed the new kernel. Reinstall these. (Modules that have been integrated into newer kernels will have been removed.)

Edit: One more tip -

Before adding any new kernel, check your /boot/grub/menu.lst to see if there is a stanza to boot the existing kernel by name. If not, create one, or you will not be able to boot back to the older kernel once the new one is installed, should the new one not work properly with your specific hardware.

[wharfhouse]

Hi Neal and thanks for the tips... I'm logging off now so have a good day