an /etc/modprobe.d/ not working as it did in centos 6.9

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rubberband
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Joined: 2019/07/09 23:21:36

an /etc/modprobe.d/ not working as it did in centos 6.9

Post by rubberband » 2019/07/09 23:41:20

I'm trying to update some older servers to something modern.

On one of them, I've re-OSed from Centos 6.9 to Centos 7.6.1810. There are all small Dell servers, this particular one is a PowerEdge R630 with Intel X520 networking. The ixgbe driver doesn't really like the trancievers but they do work. On 6.9, I had a file:

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$ cat /etc/modprobe.d/ixgbe.conf 
options ixgbe allow_unsupported_sfp=1
$
That allowed these to work. On 7.6, that same file does not work. When I boot the system, I have no em1 / em2 devices. (I do have an em3 and em4, but those are slower.) The option is still supported by the driver because if I manually run on console:

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# modprobe –r ixgbe && modprobe ixgbe allow_unsupported_sfp=1
# service network stop
# service network start
The em1 and em2 devices appear and get configured.

What is the proper 7.6 way to make this a persistent boot time configuration?

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TrevorH
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Re: an /etc/modprobe.d/ not working as it did in centos 6.9

Post by TrevorH » 2019/07/09 23:57:38

It works exactly the same way as it did in 6.x. The drivers are loaded from inside the initramfs during boot and /etc/modprobe.d is included in the initramfs at the time that it's built. So there are a few ways to fix this, the first one, if your current kernel is not 3.10.0-957.21.3.el7.x86_64 then you can just yum update and it will install the latest kernel, build an initramfs file for it and include your modprobe.d file at the same time. If you already have that kernel then you could yum reinstall it (by full version number) and that will do it too. Or you can run dracut -f --kver=$(uname -r) and it will rebuild it and replace the one for the running kernel.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

rubberband
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Joined: 2019/07/09 23:21:36

Re: an /etc/modprobe.d/ not working as it did in centos 6.9

Post by rubberband » 2019/07/10 00:32:51

Okay, the "dracut" command fixed it. I must have forgotten to document that step last time.

Thanks.

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TrevorH
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Re: an /etc/modprobe.d/ not working as it did in centos 6.9

Post by TrevorH » 2019/07/10 07:36:41

Could also be that it's one of those things that fixes itself when you're not looking. If you create the modprobe file and then do your standard `yum update` during installation then it would be ok as the updated kernel would pick up the new file and include it. If you do it the other way around then it won't.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

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