How should one reload udev rules, so that newly created one can function?
I'm running Arch Linux, and I don't have a
udevstart command here.
/etc/rc.d, no udev service there.
Udev uses the inotify mechanism to watch for changes in the rules directory, in both the library and in the local configuration trees (typically located at
/etc/udev/rules.d). So you don't need to do anything when you change a rules file.
You only need to notify the udev daemon explicitly if you're doing something unusual, for example if you have a rule that includes files in another directory. Then you can use the usual convention for asking daemons to reload their configuration: send a SIGHUP (
pkill -HUP udevd). Or you can use the
udevadm control --reload-rules.
The udev rules are only applied when a device is added. If you want to reapply the rules to a device that is already connected, you need to do this explicitly, by calling
udevadm trigger with the right options to match the device(s) whose configuration has changed, e.g.
udevadm trigger --attr-match=vendor='Yoyodyne' --attr-match=model='Frobnicator 300'.
I'm adding this because some day I will need it... again.
Sometimes you get an incorrect matching of ethernet device numbers and MAC addresses. Sometimes this is really important, like when running in a VM and each device is assigned to a different VLAN.
/etc/udev/rules.d/70-persistent-net.rules(or its equivalent)
udevadm control --reload-rules
udevadm trigger --attr-match=subsystem=net
I was surprised how well this worked.
I am not sure if this applies, and this is definitely an older post but it came up pretty high my web search for udev info so I thought I might share some knowledge.
You can trigger udev rules manually for specific devices. This applies only to redhat-related distros (centos fedora etc etc etc)
Once you make the relevant changes in your rules file (
/etc/udev/rules.d/whateveryoucalledyourrules), you can echo
change in to the device's uevent.
echo change > /sys/block/devname/partname1/uevent
This will force a udev rule reading for ONLY this device. Much better, and more targeted in my opinion.
For me, below command sequence has worked as it is desired.
I have done modifications in
/etc/udev/rules.d/70-persistent-net.rules to change the
eth number and to reload them without rebooting.
/etc/init.d/networking stop /etc/init.d/udev stop udevadm control --reload-rules /etc/init.d/udev start /etc/init.d/networking start
By following this, It was successfully loaded in run time without rebooting the machine.
Any suggestion or recommendations on this are welcome, as I have discovered this on my own by reading the man pages.
I'm adding the correct answer here because it took me a while to notice it in the comment from @enthusiasticgeek. All you need to do (assuming you are on the console of the server - clearly this is bad to do if you are ssh'd in!):
cat /etc/udev/rules.d/70-persistent-net.rules | grep "PCI device" | perl -pe 's/.*\((\w+)\).*/$1/g'| uniq
In my case, it's
igb, so it prints just that.
sudo rmmod igb(replace
igbwith your card driver obtained from step 1.
/etc/udev/rules.d/70-persistent-net.rules as needed, then load the module again using
modprobe igb, again replacing
igb with yours.