udev/hotplug?

John Wendel john.wendel at metnet.navy.mil
Tue May 29 20:55:54 UTC 2007


Phil Meyer wrote:
> Ashley M. Kirchner wrote:
>>
>>    If I don't have anything that's either hotpluggable, or going to be 
>> hotplugged on a machine, is there any reason why I should have udev 
>> running?  How can I shut it off?  (I can't remove it because of all 
>> the dependencies with other stuff.)
>>
> 
> No, you cannot remove it.  All devices, including permanent stationary 
> devices are managed by udev.
> 
> udev and hal together manage removable devices.
> 
> What you will find, is an empty /dev without udev. :)  Not very useful.
> 
> There are three layered pieces to device and driver management in Fedora.
> 
> 1.   kuzdu discovers devices and manages /etc/sysconfig/hwconf
> 2.   udev creates all device entries based upon rules on /etc/udev/rules.d
> 3.   hal will take over management of certain devices that udev creates, 
> such as pluggable devices, and cdrom and DVD -payers.
> 
> 
> This is an over simplification to illustrate what would happen if you 
> pulled out udev.  The structure would collapse. :)
> 
> Other Linux distros substitute other device discovery tools for kudzu, 
> but the other two layers are present in  all modern distros that use a 
> 2.6 kernel.
> 
> So, it could also be described this way:
> 
> 1.   Device discovery tool.
> 2.   udev
> 3.   hal (optional)
> 
> 
> Good luck!
> 

WARNING! I HAVEN'T TRIED THIS !

You should be able to get rid of udev by populating a real /dev 
directory using MAKEDEV (this assumes that Fedora has been maintaining 
MAKEDEV).  You'll need to boot from a rescue disk and then build /dev.

Before rebooting to the real system, "mv udev udev.old" and "ln -s 
/bin/true udev".

Let us know the result if you try it.

Regards,

John




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