I did a bulk "yum update -y" of several servers. As a sanity check after the upgrade, I ran a grep of /etc/grub.conf across all updated servers looking to ensure the kernel I expected was installed.
Two servers came up saying /etc/grub.conf did not exist!
I logged into the servers, and /etc/grub.conf was a broken link. (It points to /boot/grub/grub.conf). My systems are all setup with a dedicated /boot partition. Sure enough, /boot was not mounted. Furthermore, I saw no /boot entry in /etc/fstab (which all my other servers contain).
So I mounted /boot, and the the grub.conf file was not consistent: it did not have a stanza for the kernel I wanted installed. So I did a "yum remove kernel ; yum install -y kernel". Both the remove and the install resulted in this message getting printed:
grubby fatal error: unable to find a suitable template
Just for kicks, I renamed both the /etc/grub.conf symlink as well as the actual /boot/grub/grub.conf file, and repeated the kernel remove/install. This did NOT produce the above error; however, no symlink or actual grub.conf file was created.
I did a little web searching on the above error, and one common cause is that there is no valid "title..." stanza in the grub.conf file for grubby to use as a template. But my file does in fact contain a valid stanza.
I even copied a valid grub.conf file from another server, and re-ran the kernel remove/install: same error.
Clearly, something is broken, but I'm not sure what. Anyone seen anything like this?
By the way, these machines were all 5.something, being upgraded to 5.7.
Thanks!