[CentOS-virt] 4.9 kernel fails to boot because it didn't have the mpt3sas module

Wed May 17 17:07:36 UTC 2017
Sarah Newman <srn at prgmr.com>

On 05/16/2017 09:04 PM, Jerry wrote:
<snip>
> 
> Turns out dracut was unable to mount the root file system.  So I went back
> into the 3.10 kernel again to see if the mpt2sas or mpt3sas driver was in
> its initramfs file... and it wasn't:
> 
> 
> $ sudo lsinitrd -k 4.9.25-27.el7.x86_64 | grep mpt
> -rw-r--r--   1 root     root            0 May 16 12:39 etc/fstab.empty
> -rw-r--r--   1 root     root           22 Nov  5  2016
> usr/lib/kbd/unimaps/empty.uni
> 
> For comparison:
> 
> $ sudo lsinitrd -k 3.10.0-514.16.1.el7.x86_64 | grep mpt
> -rw-r--r--   1 root     root            0 May 16 04:37 etc/fstab.empty
> -rw-r--r--   1 root     root           22 Nov  5  2016
> usr/lib/kbd/unimaps/empty.uni
> drwxr-xr-x   2 root     root            0 May 16 04:37
> usr/lib/modules/3.10.0-514.16.1.el7.x86_64/kernel/drivers/scsi/mpt3sas
> -rw-r--r--   1 root     root       379021 Apr 12 08:51
> usr/lib/modules/3.10.0-514.16.1.el7.x86_64/kernel/drivers/scsi/mpt3sas/mpt2sas.ko
> 
> 
> So I added it:
> 
> 
> $ sudo dracut --force --add-drivers mpt3sas --kver=4.9.25-27.el7.x86_64
> $ sudo lsinitrd -k 4.9.25-27.el7.x86_64 | grep mpt
> Arguments: --force --add-drivers 'mpt3sas' --kver '4.9.25-27.el7.x86_64'
> -rw-r--r--   1 root     root            0 May 16 12:57 etc/fstab.empty
> -rw-r--r--   1 root     root           22 Nov  5  2016
> usr/lib/kbd/unimaps/empty.uni
> drwxr-xr-x   2 root     root            0 May 16 12:57
> usr/lib/modules/4.9.25-27.el7.x86_64/kernel/drivers/scsi/mpt3sas
> -rwxr--r--   1 root     root       374152 May 16 12:57
> usr/lib/modules/4.9.25-27.el7.x86_64/kernel/drivers/scsi/mpt3sas/mpt3sas.ko
> 
> 
> After this I was able to get the 4.9 kernel to boot and Xen is now working.

You should be able to make this change permanently from /etc/dracut.conf with
the add_drivers+= line, or build a generic initrd with hostonly="no" .

I don't know why it wasn't originally added.

--Sarah