Dell's "helpful" new network device names

Traditionally on Linux hosts, your Ethernet devices are prefixed with eth, so your primary Ethernet port is eth0, followed by eth1, etc. Almost every Linux distro follows this (for wired LAN interfaces - wireless is a whole other bag). It makes things like scripting network configuration in your automated installers a lot easier, since you know the primary interface should almost always be named eth0 (there are some exceptions, but we deal with those as they come).

That is until Dell decided to change their naming scheme for RHEL 6 hosts.

Under the New World Order, Dell has "helpfully" decided to rename network interfaces emX for onboard devices, pX for PCI-slot cards. Now, I sort of understand their reason for doing this. There are some cases where network devices will be enumerated differently, particularly when using PCI-based network cards, and also when switching kernel versions. This can result in unwanted changes to your network order, where eth1 suddenly becomes eth0, or eth[0-3] disappear and become eth[4-7]. This problem can be mitigated by leveraging UDev's persistent network interface naming, which is precisely what Dell has done.

I think they went a step too far though, especially since emX is not a standard across server platforms. For Dell-only sites, this isn't a big issue, since all of your hardware will follow that paradigm. When your install scripts depend on interfaces being named eth0, however, things break horribly.

Fortunately you can disable this "feature" by specifying "biosdevname=0" as a kernel boot argument.