When grub goes to stage 2, it will present the kernel selection menu.
The best way to configure this is to use either the SAN disk or the local disk as your MBR (master boot record) then update the
/boot/grub/grub.conf file to include both stanza entries from the local HDD and the SAN disk.
Then use the
default=0 entry to set the default OS kernel to load.
kernel /boot/vmlinuz-18.104.22.168-34-default root=/dev/hda1 vga=0x317 showopts
### SAN stanza entry ###
kernel /boot/vmlinuz-22.214.171.124-34-default root=/dev/sda1 vga=0x317 showopts
The second entry will be
It may be better to boot from the SAN disk as you will be using the UEFI to load the fibre storage.
Manually editing grub
If you are unsure the local device number then you can go to the
command-line entry when presented with the
grub menu at boot time:
If you have the
hiddenmenu setting in your
grub.conf then it will say something similar to:
Booting from Red Hat 126.96.36.199-34... in 3 seconds ....
Press Esc to get to the menu:
Use the ^ and v keys to select which entry is highlighted.
Press enter to boot the selected OS, 'e' to edit the
commands before booting, 'a' to modify the kernel arguments
before booting, or 'c' for a command-line.
At this point you can enter c and enter various root settings to get the correct disk setting:
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0x83