[centos] Modify grub.conf

[FN-GM]

Hello,

 

I have this problem described on this forum post and there is a fix! Link here - https://community.freepbx.org/t/freepbx-in-hyperv/48721/13?u=fn_gm

 

Can someone please explain what he means by saying "Put it at the end of the kernel line" please? I copy of my grub.conf is below.

 

I not a Linux expert so want to be 100% sure before I tinker.

 

Thanks

 

 

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/sda2
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
#hiddenmenu
title Sangoma Linux (3.10.0-862.9.1.el7.x86_64) 7 (Core)
root (hd0,0)
kernel /vmlinuz-3.10.0-862.9.1.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-3.10.0-862.9.1.el7.x86_64.img
title Sangoma Linux (3.10.0-862.6.3.el7.x86_64) 7 (Core)
root (hd0,0)
kernel /vmlinuz-3.10.0-862.6.3.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-3.10.0-862.6.3.el7.x86_64.img
title Sangoma Linux (3.10.0-862.2.3.el7.x86_64) 7 (Core)
root (hd0,0)
kernel /vmlinuz-3.10.0-862.2.3.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-3.10.0-862.2.3.el7.x86_64.img

[ZeroHour]

Put it at the end of:

title Sangoma Linux (3.10.0-862.9.1.el7.x86_64) 7 (Core)
   root (hd0,0)
   [b]kernel /vmlinuz-3.10.0-862.9.1.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet[/b]
   initrd /initramfs-3.10.0-862.9.1.el7.x86_64.img

With a space.

Dont add it to all your kernel lines in case it goes wrong, you should be able to boot to an older kernel version at least as long as they have not auto removed.

Take an snapshot in hyperv as well

Edited October 10, 2018 by ZeroHour

[FN-GM]

Would this config be correct please?

 

Thanks for your help.

 

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/sda2
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
#hiddenmenu
title Sangoma Linux (3.10.0-862.9.1.el7.x86_64) 7 (Core)
root (hd0,0)
kernel /vmlinuz-3.10.0-862.9.1.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet clocksource_failover=acpi_pm
initrd /initramfs-3.10.0-862.9.1.el7.x86_64.img
title Sangoma Linux (3.10.0-862.6.3.el7.x86_64) 7 (Core)
root (hd0,0)
kernel /vmlinuz-3.10.0-862.6.3.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-3.10.0-862.6.3.el7.x86_64.img
title Sangoma Linux (3.10.0-862.2.3.el7.x86_64) 7 (Core)
root (hd0,0)
kernel /vmlinuz-3.10.0-862.2.3.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-3.10.0-862.2.3.el7.x86_64.img

[ZeroHour]

Would this config be correct please?

 

Thanks for your help.

 

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/sda2
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
#hiddenmenu
title Sangoma Linux (3.10.0-862.9.1.el7.x86_64) 7 (Core)
   root (hd0,0)
   kernel /vmlinuz-3.10.0-862.9.1.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet clocksource_failover=acpi_pm
   initrd /initramfs-3.10.0-862.9.1.el7.x86_64.img
title Sangoma Linux (3.10.0-862.6.3.el7.x86_64) 7 (Core)
   root (hd0,0)
   kernel /vmlinuz-3.10.0-862.6.3.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
   initrd /initramfs-3.10.0-862.6.3.el7.x86_64.img
title Sangoma Linux (3.10.0-862.2.3.el7.x86_64) 7 (Core)
   root (hd0,0)
   kernel /vmlinuz-3.10.0-862.2.3.el7.x86_64 ro root=UUID=d18da6e9-f0a3-4797-996f-3d9db2061993 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
   initrd /initramfs-3.10.0-862.2.3.el7.x86_64.img

 

Yeah that *should* work. Just double check its added when you upgrade your kernel next time. *Normally* variables get rolled up with kernel upgrades but its always better to check so I would put a note in to remind yourself on the MOTD on that server. I have not had to do the exact addition you are making before but I have added variables to the kernel before with AWS AMI linux.

[FN-GM]

Thanks for that. It has booted. Hopefully it will fix my problem.

[Jamo]

Just a quick heads up, depending on the distro (i'm not familiar with freepbx) there is often a script which runs which updates the grub config (for example when a kernel is updated via the package manager)

 

That will usually take a set of defaults (rhel/centos this is /etc/sysconfig/grub, and debian usually /etc/default/grub). If these files exist then you normally need to edit the lines within there rather than in the file direct as it will just get blatted during the next update

[FN-GM]

Cheers! I will check it next time I run updates.