Error changing net interface name 'ibft0' to 'ens3': Device or resource busy

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Environment

SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server 15

Situation

A network interface name is ens3 as default and when booting over iSCSI using iBFT, the interface name will show up as ibft0. The following message is shown in dmesg.

systemd-udevd[1107]: Error changing net interface name 'ibft0' to 'ens3': Device or resource busy

Resolution

This is by design when using iBFT but there is a workaround.

Workaround:

1. Ensure the file exists: /etc/sysconfig/network/ifcfg-ens3. "ens3" will be used as an example here. If the ifcfg-ens3 file does not exits and unnecessary ifcfg-* file (e.g. ifcfg-ibft0) exists, rename the file to ifcfg-ens3 and correct values in the file appropriately if needed.

2. Run dracut -f to update the initrd.

   # dracut -f

3. Add ifname the GRUB.cfg file

   # vi /etc/default/grub
   ...
   GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 ... crashkernel=72M,low ifname=ens3:xx:xx:xx:xx:xx:xx"
   ...

   xx:xx:xx:xx:xx:xx is MAC address for ens3

   # grub2-mkconfig -o /boot/grub2/grub.cfg

Then reboot the server.

Cause

The kernel command includes rd.iscsi.ibft=1 and rd.iscsi.firmware=1.

# man dracut.cmdline
...
rd.iscsi.ibft rd.iscsi.ibft=1: Turn on iBFT autoconfiguration for the interfaces
...

Disclaimer

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