Check out my first novel, midnight's simulacra!

Udev: Difference between revisions

From dankwiki
No edit summary
Line 4: Line 4:


==[[KVM]]==
==[[KVM]]==
On [[Debian]] (unstable, 2009-06-20), the default [[kvm]]/udev setup results in <tt>/dev/kvm</tt> have mode 0666 and ownership <tt>root:root</tt>, despite the creation of a <tt>kvm</tt> group. To have this file instead created with <tt>root:kvm</tt> ownership, add <tt>/etc/udev/rules.d/50-kvm.rules</tt> with the contents:<pre>KERNEL=="kvm", NAME="%k", GROUP="kvm", MODE="0660"</pre>I got this information from [https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/127704 Ubuntu bug 127704].
On [[Debian]] (unstable, 2009-06-20), the default [[kvm]]/udev setup results in <tt>/dev/kvm</tt> have mode 0666 and ownership <tt>root:root</tt>, despite the creation of a <tt>kvm</tt> group. To have this file instead created with <tt>root:kvm</tt> ownership, add <tt>/etc/udev/rules.d/50-kvm.rules</tt> with the contents:<pre>KERNEL=="kvm", NAME="%k", GROUP="kvm", MODE="0660"</pre>I got this information from [https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/127704 Ubuntu bug 127704], and have reported it to [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=493053 Debian bug 493053].

Revision as of 12:26, 21 June 2009

udev is introduced by the sparse website at http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html. It extended, superseded and utterly replaced devfs, a turn-of-the-century abortion birthed by Richard Gooch (for details on this gory struggle (long since settled in udev's favor), see Greg Kroah-Hartman's whitepaper, 'udev and devfs - the final word'. It implements device naming for Linux systems -- that is, maps kernel hardware entities to userspace keys. Furthermore, it emits low-level DBus messages; clients such as HAL can listen to these events and perform arbitrarily complex actions. udev is made up of both a kernel component (included in 2.6 Linux kernels; 2.6.19 is the minimum recommended version as of this writing (see the kernel documentation)) and a userspace daemon (udevd) plus its configuration.

Interface naming

KVM

On Debian (unstable, 2009-06-20), the default kvm/udev setup results in /dev/kvm have mode 0666 and ownership root:root, despite the creation of a kvm group. To have this file instead created with root:kvm ownership, add /etc/udev/rules.d/50-kvm.rules with the contents:

KERNEL=="kvm", NAME="%k", GROUP="kvm", MODE="0660"

I got this information from Ubuntu bug 127704, and have reported it to Debian bug 493053.