http://fedoraproject.org/wiki/Features/ConsistentNetworkDeviceNaming
- Servers often have multiple Ethernet ports, either embedded on the motherboard, or on add-in PCI cards. Linux has traditionally named these ports ethX, but there has been no correlation of the ethX names to the chassis labels - the ethX names are non-deterministic.
Starting in Fedora 15, Ethernet ports will have a new naming scheme corresponding to physical locations, rather than ethX. Ethernet ports embedded on server motherboards will be named em<port_number>, while ports on PCI cards will be named p<slot_number>p<port_number>,
corresponding to the chassis labels. Additionally, if the network device is an SR-IOV Virtual Function or has Network Partitioning (NPAR) capability, the name will have a suffix of _<virtual_function> or _<partition>.
By changing the naming convention, system administrators will no longer have to guess at the ethX to physical port mapping, or invoke workarounds on each system to rename them into some "sane" order.
This feature affects all physical systems that expose network port naming information in SMBIOS 2.6 or later (specifically field types 9 and 41). Dell PowerEdge 10G and newer servers (PowerEdge 1950 III family, PowerEdge R710 family, and newer), and HP ProLiant
G6 servers and newer are known to expose this information, as do some newer desktop models. Furthermore, most older systems expose some information in the PCI IRQ Routing Table, which will be consulted if information is not provided by SMBIOS.
Fedora running as a guest virtual machine will continue to use the ethX names.
Existing installations upgraded to Fedora 15 will not see a change in names unless /etc/udev/rules.d/70-persistent-net.rules is deleted and the HWADDR lines are removed from all /etc/sysconfig/network-scripts/ifcfg-* files, and those files are renamed to
use the new device names.
You may continue to write rules in /etc/udev/rules.d/70-persistent-net.rules to change the device names to anything you wish. Such will take precedence over this physical location naming scheme. Such rules may look like:
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:11:22:33:44:55", ATTR{type}=="1", KERNEL=="eth*", NAME="public"
This feature may be disabled by passing "biosdevname=0" on the kernel command line, in which case, behavior will revert to using ethX names.
Upgrading from an earlier version of Fedora (including 15-Alpha or -Beta) to Fedora 15 may result in a change of network device names from an earlier biosdevname naming scheme to the final naming scheme described here. Configuration files must be manually
adjusted accordingly.
简单的说想恢复到传统的命名方式，只要在kernel command line 里加上biosdevname=0就可以了，修改grub2 kernel command line的路径为：/etc/default/grub