I would advise you to follow https://help.ubuntu.com/community/DiskSpace#BIOS-Boot_or_EFI_partition_.28required_on_GPT_disks.29 .
The proper solution depends on what exactly are you trying to achieve.
If you want to boot via EFI:
- backup all your data since changing partition layout in non-proffesional way will destroy them
parted /dev/X substitute X for device name that represents your drive
- create the partitions as follows: (adjust sizes and flags to match your current partitons if you want to prevent the data loss)
Number Start End Size File system Name Flags
1 144GB 145GB 512MB fat16 EFI System Partition boot, esp
2 145GB 145GB 512MB ext4
3 145GB 236GB 90.2GB lvm
- format your newly created partitions:
mkfs.vfat /dev/X1 and
- your vfat partition represents the /boot/efi mount point
- your ext4 partition represents the /boot mount point
Here's an example of my fstab:
UUID=15612dd9-fa37-43d5-ba89-81224473779c /boot ext4 defaults 1 2
UUID=9B5B-30A6 /boot/efi vfat umask=0077,shortname=winnt 0 2
afterwards you should be able to run the grub2-install that should take care of the rest.
If however you'd prefer to boot via (legacy) BIOS Boot then you need MBR formatted partition then try to follow the steps for the EFI but create just one partiton and mount it under /boot + populate fstab accordingly.