From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: Provide ability to change default netdev name? Date: Fri, 16 Aug 2013 16:48:38 -0700 Message-ID: <520EBA56.4050301@candelatech.com> References: <520EA43F.2010304@candelatech.com> <1376696468.11042.74.camel@deadeye.wl.decadent.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev To: Ben Hutchings Return-path: Received: from mail.candelatech.com ([208.74.158.172]:51641 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753665Ab3HQAPB (ORCPT ); Fri, 16 Aug 2013 20:15:01 -0400 In-Reply-To: <1376696468.11042.74.camel@deadeye.wl.decadent.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: On 08/16/2013 04:41 PM, Ben Hutchings wrote: > On Fri, 2013-08-16 at 15:14 -0700, Ben Greear wrote: >> The latest udev in Fedora 19 (and perhaps elsewhere) will no longer >> implement rules that rename an interface from ethX to ethY. Nor >> wlanX or other 'kernel namespaces'. The Fedora udev developers do not seem >> interested in changing this back to the old behaviour, evidently they >> had a hard time implementing it properly. > > There is an inherent problem that a new device can appear at any time > under the exact name udev is trying to rename to. I expect it is > possible to do this properly but may be quite difficult to eliminate the > possibility of deadlock. > > Still, if udev actively refuses to use the 'kernel namespaces' (rather > than just being configured not to), that would be a bug. I agree, but the Fedora udev developers do not. I'm not sure if other distros will follow or not. >> This effectively makes it impossible to have network device names of ethX >> consistent across reboots in systems with multiple NICs and/or drivers. >> >> One way to work around this would be allow the kernel to use a different >> default netdev name (for instance, keth%d). I'm thinking this would be >> configured as a kernel command line argument. Then, a small change to udev/systemd to >> make the 'kernel namespaces' configurable by letting it understand this new kernel >> command line argument should resolve the problem. >> >> Does this sound like something that could be accepted upstream? > > This sounds completely ridiculous. Yeah, seems lame to hack around funky user-space, but if udev folks will truly not fix this, then life is going to suck for users wanting to use 'ethX' naming schemes for their network devices. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com