During the install, you may need to reboot multiple times. (Sometimes you fail to boot over and over...)
After a while, typing the same 8 boilerplate mount commands every time you reboot back into the LiveCD environment gets overly time consuming.
The solution? Make a script to make your life faster and easier. Actually I've already made one, Here is how you would use it:
1 - Run the main mount command for your root partition, (use the specific disk partition that applies to your system)
This is the main command you should still run by hand, (this is done manually still because it has to know where to store/access the script)
mount /dev/nvme0n1p3 /mnt/gentoo
2a - Either, Download and save the script in this mounted root directory.
wget https://dpaste.com/5ZB6TH4PW.txt -O mountcommands.sh
2b - Or, Alternatively copy and paste it from this wiki:
#!/bin/sh mount --types proc /proc /mnt/gentoo/proc mount --rbind /sys /mnt/gentoo/sys mount --make-rslave /mnt/gentoo/sys mount --rbind /dev /mnt/gentoo/dev mount --make-rslave /mnt/gentoo/dev mount --bind /run /mnt/gentoo/run mount --make-slave /mnt/gentoo/run
3 - Make it executable
chmod a+x mountcommands.sh
4 - Execute it! Done! (the ./ is needed - means run from current directory)
Now everytime you reboot, repeat only Step 1 and Step 4.
It will be saved in the root directory of your gentoo partition.
From there you can "chroot /mnt/gentoo" to enter the chroot.
And "mount /boot" to mount your other important disks/partitions, using fstab, once you are inside.