Solved: Not able to see console after POST in Redhat Enterprise Linux or Centos.

Some Linux Operating Systems, or RHEL versions sometimes disable console video and you might be not able to see remote console after POST.

This happens due to a kernel issue once POST(Power on Self Test) is completed and system booted.

The issue is caused by the fact that on boot past POST the kernel wants to switch to a graphical video mode which is not supported by the iLO’s virtual console.

The fix is to add “nomodeset” to the kernel line(s) in /boot/grub/grub.conf and reboot.

Lets look at an example below:

# 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/mapper/rootvg-rootlv
 #          initrd /initrd-[generic-]version.img
 #boot=/dev/sda
 default=0
 timeout=3
 password --md5 $1$4fRD1$h/SLYahhhhedw/yauSnogggyje
 splashimage=(hd0,0)/grub/splash.xpm.gz
 hiddenmenu
 title Red Hat Enterprise Linux Server (3.10.0-693.33.1.rt56.621.el6rt.x86_64)
         root (hd0,0)
         kernel /vmlinuz-3.10.0-693.33.1.rt56.621.el6rt.x86_64 ro root=/dev/mapper/rootvg-rootlv rd_NO_LUKS rd_LVM_LV=rootvg/rootlv rd_LVM_LV=rootvg/swap01lv LANG=en_GB rd_NO_MD SYSFONT=latarcyrheb-sun16  KEYBOARDTYPE=pc KEYTABLE=uk pci=bfsort  rd_NO_DM rhgb quiet crashkernel=auto nomodeset
         initrd /initramfs-3.10.0-693.33.1.rt56.621.el6rt.x86_64.img
 title Red Hat Enterprise Linux Server (3.10.0-693.5.2.rt56.592.el6rt.x86_64)
         root (hd0,0)
         kernel /vmlinuz-3.10.0-693.5.2.rt56.592.el6rt.x86_64 ro root=/dev/mapper/rootvg-rootlv rd_NO_LUKS rd_LVM_LV=rootvg/rootlv rd_LVM_LV=rootvg/swap01lv LANG=en_GB rd_NO_MD SYSFONT=latarcyrheb-sun16  KEYBOARDTYPE=pc pci=bfsort  rd_NO_DM rhgb quiet crashkernel=auto nomodeset
         initrd /initramfs-3.10.0-693.5.2.rt56.592.el6rt.x86_64.img
 title Red Hat Enterprise Linux Server (3.10.0-514.rt56.210.el6rt.x86_64)
         root (hd0,0)
         kernel /vmlinuz-3.10.0-514.rt56.210.el6rt.x86_64 ro root=/dev/mapper/rootvg-rootlv rd_NO_LUKS rd_LVM_LV=rootvg/rootlv rd_LVM_LV=rootvg/swap01lv LANG=en_GB rd_NO_MD SYSFONT=latarcyrheb-sun16  KEYBOARDTYPE=pc KEYTABLE=uk pci=bfsort  rd_NO_DM rhgb quiet crashkernel=auto nomodeset
         initrd /initramfs-3.10.0-514.rt56.210.el6rt.x86_64.img 

We have added “nomodeset” keyword in front of each kernel line and now the system will reboot with this option and hence will not set any mode when taking this server remote console.

Now we will be able to take the console.

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