How I can set grub to only boot a certain kernel once? (CentOS)
 

How I can set grub to only boot a certain kernel once? (CentOS)

Is it possible to do through grub.conf?

grub-reboot isn't found for CentOS.

TIA

besides the normal
during boot hit any key and use the down arrow to select one of the other three back-up kernels

but you could edit the legacy grub "grub.conf" and make an old one the boot priority

The problem is I don't have console access, I can only remote reboot it, so if it kernel panics, or doesn't have the right nic module loaded, then I will be unable to change the kernel.

in grub.conf
change "default=0" to default=1 or 2 or 3
then change it back when it is fixed

How do I change it if I don't have access to the server after it didn't come back up after rebooting with the new kernel?

You can't :( (obviously). You need physical access if the system won't boot at all. You'll need to boot off a rescue cd or install media to edit it.

If it partially boots, a remote serial console or ILO unit might suffice.