On 06/06/2011 12:47 AM, Ted Ts'o wrote:
> Were there any messages in the syslog before this relating to ext4 or
> jbd2?
> 
>> Jun  5 20:34:12 box kernel: JBD2: Detected IO errors while flushing file
>> data on sdc1-8
>> Jun  5 20:34:12 box kernel: Aborting journal on device sdc1-8.
>> Jun  5 20:34:12 box kernel: JBD2: I/O error detected when updating
>> journal superblock for sdc1-8.
> 
> For example, anything like these messages *before* the oops messages?
> 
>     	     	      	   	 	  	       - Ted

Of course. I am attaching all relevant log.

The box had a USB disk attached. Unfortunately the USB code detected
only a slow link:
Jun  3 08:36:26 box kernel: usb 2-1: not running at top speed; connect
to a high speed hub

A job was still copying a large file when I disconnected the disk
accidentially two hours later. Of course ext4 didn't like that. But
clearly the Oops should not have happened.

Thanks.

Ortwin