Messages in this thread | | | Date | Mon, 11 Sep 2006 15:36:06 -0400 | From | Bill Davidsen <> | Subject | Re: [PATCH 2.6.18-rc5] PCI: sort device lists breadth-first |
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Arjan van de Ven wrote: > On Fri, 2006-09-08 at 11:18 -0500, Matt Domsch wrote: >> On Fri, Sep 08, 2006 at 11:56:39AM -0400, Dave Jones wrote: >>> On Thu, Sep 07, 2006 at 10:14:22PM -0500, Matt Domsch wrote: >>> > Problem: >>> > New Dell PowerEdge servers have 2 embedded ethernet ports, which are >>> > labeled NIC1 and NIC2 on the chassis, in the BIOS setup screens, and >>> > in the printed documentation. Assuming no other add-in ethernet ports >>> > in the system, Linux 2.4 kernels name these eth0 and eth1 >>> > respectively. Many people have come to expect this naming. Linux 2.6 >>> > kernels name these eth1 and eth0 respectively (backwards from >>> > expectations). I also have reports that various Sun and HP servers >>> > have similar behavior. >>> >>> This came up years back when 2.6 was something new, and the answer >>> then was 'bind the interface to the MAC address'. >> Both Red Hat-based distros and openSuSE-based distros do something >> like this with configuration files automatically. Red Hat's >> anaconda/kudzu puts the HWADDR lines in the generated >> /etc/sysconfig/network-scripts/ifcfg-* files. openSuSE's udev rules >> puts lines in /etc/udev/rules.d/30-net_persistent_names.rules the >> first time it discovers a new interface. Both methods are intended to >> maintain a persistent name for each NIC, after being set up the first >> time. Neither deals well with replacing one NIC with another - you >> must edit the config files. >> >> This works pretty well post-install. It doesn't work well at install >> time, all the installers use the kernel's original names, and then >> those names become the persistent names in the config files. >> >> >>> Whilst your patch will fix the case that's currently broken (2.4->2.6), >>> doesn't it offer equal possibility to break existing setups when people move >>> from <=2.6.18 -> 2.6.19 ? >> If they're using config files / udev rules as suggested, it shouldn't >> break them. >> >> If they're not, then yes, this could. Debian's >> /etc/network/interfaces file allows use of hwaddr fields, though by >> default it doesn't appear anything sets it up. >> >> I'm open to suggestions on how *not* to break setups that don't use >> the MAC addresses. > > to be honest I really don't like the PCI ordering change thing for this. > It's just too fragile altogether to cause a fixed ordering as you want. > > Maybe the kernel's initial ordering should do a numeric sort by mac > address or something.. (or userspace should) > > That wouldn't match any existing setup, and would be subject to mid-list insertions if a NIC were added/replaced. And that is fragile.
I was looking for an easy way to do PCI slot to MAC, and from there MAC to IP, so any NIC plugged into a given slot could be called eth0 (for instance) and given the "right" IP address, but that's not easy. Can be done with some searching in /sys, but it's non-trivial.
-- Bill Davidsen <davidsen@tmr.com> Obscure bug of 2004: BASH BUFFER OVERFLOW - if bash is being run by a normal user and is setuid root, with the "vi" line edit mode selected, and the character set is "big5," an off-by-one errors occurs during wildcard (glob) expansion. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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