acam
Posts: 6
Joined: Tue Mar 13, 2012 4:08 pm

Kernel panic

Mon Jul 16, 2012 2:58 pm

I've tried disconnecting the USB hub in case it was keyboard or mouse; it isn't that.
I get the line:

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)

By the way I have started it several times successfully and noticed that the red light comes on when the USB from the powered hub is connected. The raspi doesn't boot until the mini USB power is plugged in.

Could it be the SDHC card? [It's a Sandisk 8Gb on the approved list}
Anthony Camacho

Goss1982
Posts: 13
Joined: Mon Jul 16, 2012 4:52 pm

Re: Kernel panic

Mon Jul 16, 2012 4:54 pm

Hi, a similar error code has just started to appear on my pi also. It seems to cause the pi to crash out, particulary over night time. I will see if it does it again and post the error codes. Have you checked the kernel and sys logs for anything else out of the ordinary?

acam
Posts: 6
Joined: Tue Mar 13, 2012 4:08 pm

Re: Kernel panic

Mon Jul 16, 2012 6:09 pm

I didn't know there were kernel and sys logs and have no idea how to check them out. After the kernel panis I can't enter anything with the keyboard nor can I move the mouse pointer and I don't have another linux machine that might be able to read the sdhc card.

My failure also occurred after I'd left raspberry pi on all night - but it wasn't truly on - I am powering it from a USB port on my Dell Windows computer and so (I now realise) when I switched off the computer I switched off the power to the mini-USB on the Raspberry pi - but the powered hub which I use to connect the USB keyboard and the USB mouse to one of the USB ports on the pi continues to provide some power and so the red LED stays on and the signal to the screen is maintained. I don't know whether it is a bad idea to leave the pi in this state - but when I turned on my computer this morning the pi displayed a screenful of starting messages ending with the kernel panic.
And it gets to kernel panic every time I try since then.
Anthony Camacho

Goss1982
Posts: 13
Joined: Mon Jul 16, 2012 4:52 pm

Re: Kernel panic

Tue Jul 17, 2012 2:20 pm

I think this type of error is due to some form of issue with usb devices (voltage?) as my logs showed a lot of activity with my usb connector (which happened to be attached to a powered sd reader with a 4gb card in it) prior to the crash. I have since uplugged the device and it has remained stable.

The logs can be found in /var/log/........ and with be called something like kernel and sys. This should let you see what was happening before the crash.

Can you unplug your usb hub, power the pi via the microusb connector and see if you have the same issue?

I suspect this may allow it to power on correctly as a number of post suggest you should not power the pi via the standard usb alone due to insufficient voltage?

Let me know how you get on. If you can find the logs please post anything that is relevant.

acam
Posts: 6
Joined: Tue Mar 13, 2012 4:08 pm

Re: Kernel panic

Tue Jul 17, 2012 3:29 pm

I found I had another sdhc card and thought I'd try that. it is a 16GB class 10 card brand is 'Storage Options'.

I used Win32DiskImager.exe as before to write the Debian6-19-02-2012.img to the sdhc card in a usb adapter and got 'write successful'.

So I put the card in the pi and connected the power from the Kindle charger to the mini USB socket on the pi and then connected the hub power supply which powers the keyboard and mouse.

It appears to have started correctly but there were many messages of the form "Timeout waiting for hardware interrupt". I expected to have to re-enter username and password but maybe I've forgotten the sequence I got before.

When I got to the ~$ prompt I entered startx and after a very long pause I got the midori screen; it showed the mouse arrow first and after another long pause got to midori.

It seems to be much slower than before. The brand of SDHC card isn't on either the approved list or on the list of known problem cards. I think I'll try reloading the Sandisk card again and see if it behaves better.

Anyway I suspect that leaving the pi connected to the hub and so getting some power down the USB connexion when the power from my computer USB was no longer going to the mini-USB socket in some way corrupted a file on the Sandisk sdhc card.

The solution is to rewrite the Debian image on the card.

itimpi
Posts: 1090
Joined: Sun Sep 25, 2011 11:44 am
Location: Potters Bar, United Kingdom
Contact: Website

Re: Kernel panic

Tue Jul 17, 2012 4:18 pm

That image will probably have problems with class 10 SD cards until you have successfully plated the firmware to a new er version.

You might be better of trying the Raspbian 'wheezy' image as it has the latest firmware included in the image as well as significant performance improvements.. At the moment you have to get it from the links in the Raspbian section of the forum, but I believe it will Soon also be made available via the Downloads section on www.raspberry.org

RobV
Posts: 2
Joined: Sat Jan 07, 2012 4:10 pm

Re: Kernel panic

Tue Jul 17, 2012 8:44 pm

I'm also having the same problem : after a couple of days using the Raspberry pi, it is no longer possible to boot. I have re-installed Debian several times, switched cards (class 4, 8GB). Afterwards the Pi boots again. The process is time consuming as I have to install many extra packages. The worst thing however is the feeling that the system is not reliable. As I use the Pi only through ssh and vnc. Television and keyboard is only used to enable ssh. Before pulling the power plug, the Pi is properly commanded to shutdown so the case that the image gets corrupted while there is a write ongoing, can be neglected.
I have not yet tried the Fedora or Arch distributions. Are there users of those distributions who experience the same problems ? Is this a matter of waiting for the next Debian update or is there something that can be tested or configured to get around this issue ?

Thanks for any help,
Rob

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