Udev net issues

[Joseph L. Casale]

In trying to swap a motherboard for the exact same type I kept having issues
with the NIC not being started (network manager was disabled). I finally found
70-persistent-net.rules under udev had the mac address of the old nic as eth0
so I moved this file out and rebooted only to see it was recreated as expected
but had the old mac address? I finally edited the mac address and that worked.

Where in the world would it have gotten the old mac from?

Thanks,
jlc

[Mikkel]

Joseph L. Casale wrote:
> In trying to swap a motherboard for the exact same type I kept having issues
> with the NIC not being started (network manager was disabled). I finally found
> 70-persistent-net.rules under udev had the mac address of the old nic as eth0
> so I moved this file out and rebooted only to see it was recreated as expected
> but had the old mac address? I finally edited the mac address and that worked.
>
> Where in the world would it have gotten the old mac from?
>
> Thanks,
> jlc

Check .etc.sysconfig/network-scripts/ifcfg-<interface>. Probably
ifcfg-eth0 in this case.

Mikkel

[Joseph L. Casale]

> Check .etc.sysconfig/network-scripts/ifcfg-<interface>. Probably ifcfg-eth0 in this case.
>
> Mikkel

That was the first place I looked and it was edited in the beginning. I read something about
MAKEDEV cache, could that be the culprit?

Thanks,
jlc

[Phil Meyer]

Joseph L. Casale wrote:
> In trying to swap a motherboard for the exact same type I kept having issues
> with the NIC not being started (network manager was disabled). I finally found
> 70-persistent-net.rules under udev had the mac address of the old nic as eth0
> so I moved this file out and rebooted only to see it was recreated as expected
> but had the old mac address? I finally edited the mac address and that worked.
>
> Where in the world would it have gotten the old mac from?
>
> Thanks,
> jlc

Good question, and yes, udev DOES keep track.

check in /etc/udev/rules.d for file names with *persistant* in them.  
There are several, and one for -- you guessed it -- network/NIC data.

By removing the persistent file(s), udev will rebuild it with the 
correct/current info.

This is how you install on one platform and put that disk into another.: 
Remove the udev persistant rules in the post-install.

Good Luck!

[Joseph L. Casale]

> Good question, and yes, udev DOES keep track.
>
> check in /etc/udev/rules.d for file names with *persistant* in them.
> There are several, and one for -- you guessed it -- network/NIC data.
>
> By removing the persistent file(s), udev will rebuild it with the
> correct/current info.
>
> This is how you install on one platform and put that disk into another.:
> Remove the udev persistant rules in the post-install.

Phil,
This is exactly what I did, I moved the file out altogether.
Should I have simply removed the line in it? It recreated the
file next boot with the old mac address only to still cause issues!

Thanks,
jlc

[Phil Meyer]

Joseph L. Casale wrote:
> > Good question, and yes, udev DOES keep track.
> >
> > check in /etc/udev/rules.d for file names with *persistant* in them.
> > There are several, and one for -- you guessed it -- network/NIC data.
> >
> > By removing the persistent file(s), udev will rebuild it with the
> > correct/current info.
> >
> > This is how you install on one platform and put that disk into another.:
> > Remove the udev persistant rules in the post-install.
>
> Phil,
> This is exactly what I did, I moved the file out altogether.
> Should I have simply removed the line in it? It recreated the
> file next boot with the old mac address only to still cause issues!
>
> Thanks,
> jlc

Yes, do not move (mv) the file, remove  (rm) it.  Copy it first to some 
other directory if you wish, but do not leave any trace of the original 
file anywhere udev can find it. :)

Good Luck!

[Phil Meyer]

Phil Meyer wrote:
> Joseph L. Casale wrote:
> > > Good question, and yes, udev DOES keep track.
> > >
> > > check in /etc/udev/rules.d for file names with *persistant* in them.
> > > There are several, and one for -- you guessed it -- network/NIC data.
> > >
> > > By removing the persistent file(s), udev will rebuild it with the
> > > correct/current info.
> > >
> > > This is how you install on one platform and put that disk into 
> > > another.:
> > > Remove the udev persistant rules in the post-install.
> >
> > Phil,
> > This is exactly what I did, I moved the file out altogether.
> > Should I have simply removed the line in it? It recreated the
> > file next boot with the old mac address only to still cause issues!
> >
> > Thanks,
> > jlc
>
> Yes, do not move (mv) the file, remove  (rm) it.  Copy it first to 
> some other directory if you wish, but do not leave any trace of the 
> original file anywhere udev can find it. :)
>
> Good Luck!

One further clarification:

To make a 'clean' system disk that can be put into another system, 
remove all the /etc/udev/rules.d/*persistant* and 
/etc/sysconfig/network-scripts/*eth? and 
/etc/sysconfig/network-scripts/*wlan? and /etc/X11/xorg.conf files.

I always do this in a post install, and have not tried it on a live 
system.  It may be necessary to do this from a rescue disk.  I do not 
know if a running udev will 'let you' remove that data.

Sorry to not be able to verify the steps on a previously running 
system.  I just don't do those.

However, every day I use a virtual machine on my desktop to install an 
OS on Compact Flash Cards, and thumb drives, to be used in a variety of 
equipment.  This method works perfectly for that, with the exception 
that I have to also rebuild the initrd image with drivers that anaconda 
did not see during the install.

Here is what I use, for the curious:

My %post section includes this:

#
# fix udev rules for fake interfaces
#
rm -f /etc/udev/rules.d/70-persistent-net.rules
rm -f /etc/X11/xorg.conf
#
cat << _EOF > /etc/sysconfig/network-scripts/ifcfg-eth0
#
DEVICE=eth0
BOOTPROTO=dhcp
HWADDR=
IPV6INIT=no
ONBOOT=yes
DHCP_HOSTNAME=skid
TYPE=Ethernet
_EOF
#
# make sure usb-storage is in the initrd image
#
kernel=`ls /boot/vmli* | awk -F- '{printf("%s-%s\n", $2,$3)}'`
initrd="/boot/initrd-${kernel}.img"
rm $initrd
mkinitrd --preload=ehci-hcd --preload=ahci --preload=libata 
--preload=jbd --preload=ohci-hcd --preload=uhci-hcd 
--preload=scsi_wait_scan --preload=usb-storage --preload=scsi_mod 
--preload=sd_mod --preload=pata_amd --preload=ata_generic 
--preload=pata_cs5536 --preload=pata_acpi $initrd $kernel
#

Good Luck

[Joseph L. Casale]

> One further clarification:
>
> To make a 'clean' system disk that can be put into another system,
> remove all the /etc/udev/rules.d/*persistant* and
> /etc/sysconfig/network-scripts/*eth? and
> /etc/sysconfig/network-scripts/*wlan? and /etc/X11/xorg.conf files.

I think you found the error in my way! I was running while I did it.
I'll keep this email and refer back to it next time.

Out of curiosity now, I also deleted my xorg.conf but if I leave inittab set to 5
it hangs? If I boot to 3, then init 5, it works fine? It also didn't recreate the
xorg.conf file?

Thanks for everything!
jlc

[potat0]

> To make a 'clean' system disk that can be put into another system,
> remove all the /etc/udev/rules.d/*persistant* and
> /etc/sysconfig/network-scripts/*eth? and
> /etc/sysconfig/network-scripts/*wlan? and /etc/X11/xorg.conf files.

I copied the partition to another disk, and put that to a new computer, installed grub and moved /etc/udev/rules.d/*persistent* and /etc/sysconfig/network-scripts/*eth? to /root/backups.

The system boots and seems to work, but there are no new /etc/udev/rules.d/*persistent* files, should there be?

Are the /etc/udev/rules.d/*persistent* needed? Even if those are not required can I somehow re-create those?

I do have the old ones, but I would not like to use those, I'd rather make/generate new ones if possible (and needed).

-Paavo