On Mon, Nov 17, 2008 at 2:32 AM, Berend Dekens <berend at cyberwizzard.nl> wrote: > Rudi Ahlers schreef: >> >> I have managed to kill udev on start-up (with CTRL + C), and then it boots >> up. >> So, do I need udev? And what is it's purpose? > > Udev is a device probing layer. In the old days we had a /dev system prepped > for standard use which would be complemented with other bootup scripts to > make nodes for all hardware in your system. > > Udev is the successor of this system (the one line history version anyway) > and builds up the /dev folder with all your devices. In theory this is great > but most systems (and I'm fairly sure CentOS as well) still have a number of > base nodes in /dev before udev is fully started. This helps the system boot > and in case of emergency (udev crashing or a broken probing like you have) > this would allow the system to boot and find its primary devices (if you are > lucky this might include all neccesary devices, in my case for example, when > udev won't start I only have one of 2 SATA controllers online). > > So in short, you might be able to turn off udev but adding new hardware, > plugging in usb devices or similar or starting some non-standard hardware > won't work any more. Perhaps there are more serious issues (like soft-raids > ignoring the raid and just using one drive). > > You might be able to see in the kernel console (ctrl+f10) what happens just > before the system reboots - if it is a module which fails (most likely) you > could blacklist it. That would solve the reboots. If the module is in fact > critical for some piece of hardware you might be able to tweak it instead of > disabling udev altogether. > > Do the system logs contain any clues what is going on or does the system > kills itself before logging to harddisc comes on? > > Regards, > Berend Dekens > _______________________________________________ Hi Barend, Thanx for the info :) Unfortunately I don't see anything useful in the logs. If I let it bootup by itself, then it reboots just after booting udev. If, however, I press CTRL+C the moment I see udev on the screen, I have attached a snippet from /var/log/message - which doesn't show me anything at all. -- Kind Regards Rudi Ahlers -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: kernel.txt URL: <http://lists.centos.org/pipermail/centos/attachments/20081117/510c020f/attachment-0004.txt>