I recently updated my Windows 8 install to Windows 8.1 because Windows started nagging me that there was an update. I don't boot up into Windows often, so I thought that I might as well. I found it really cool that the update was distributed through the same Windows store that you can get the Metro apps.
I went ahead and installed it, but when I rebooted to go back to work in Linux,
my GRUB bootloader wasn't able to find the information in /boot. Luckily, I
had a Debian installer disk with me and could figure out what was happening
through there.
I tried different ways of installing the bootloader, but I was really puzzled about why my GRUB install wouldn't work as it did before.
I looked at the contents of the parition table using parted
(rescue)# parted /dev/sdb print
and this is what I got:
Model: ATA ST750LM022 HN-M7 (scsi)
Disk /dev/sdb: 750GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Number Start End Size File system Name Flags
1 1049kB 1050MB 1049MB ntfs Basic data partition hidden, diag
2 1050MB 1322MB 273MB fat32 EFI system partition hidden, msftdata
3 1322MB 2371MB 1049MB fat32 Basic data partition hidden
4 2371MB 2505MB 134MB Microsoft reserved partition msftres
5 2505MB 102GB 99.6GB ntfs Basic data partition msftdata
6 102GB 103GB 367MB ntfs hidden, diag
7 103GB 153GB 50.0GB ext4 msftdata
8 153GB 693GB 540GB ext4 msftdata
9 693GB 702GB 9032MB linux-swap(v1)
10 702GB 729GB 26.8GB ntfs Basic data partition msftdata
11 729GB 750GB 21.5GB ntfs Basic data partition hidden, diag
After running the grub-install command, I was getting odd errors that I had never seen before
warning : this GPT partition label contains no BIOS boot Partition; embedding won't be possible
I didn't know quite what this meant, so that left me frustrated for quite a while until I read some docs that mentioned that I needed a new partition. This was a bit odd because I never needed that before. That is because I was previously using the pre-UEFI method of an MBR (Master Boot Record) partition table. With UEFI, many computers use a GPT (GUID Partition Table) partition table which is how my computer came installed. This new partition layout requires a BIOS boot partition.
To address this, I took the FAT32 EFI system partition (partition #2) and resized it
down by 22 MB (an arbitrary size) in order to have room for another partition
that I could designate as the BIOS boot partition. I did this using the Debian
installer's partition tool and got a new partition (partition #12). Then I used
parted to set the bios_grub flag to indicate that the partition was to be
used as a BIOS boot partition:
(rescue)# parted /dev/sdb set 12 bios_grub on
The final partition layout was
Model: ATA ST750LM022 HN-M7 (scsi)
Disk /dev/sdb: 750GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Number Start End Size File system Name Flags
1 1049kB 1050MB 1049MB ntfs Basic data partition hidden, diag
2 1050MB 1300MB 251MB fat16 EFI system partition hidden, msftdata
12 1300MB 1322MB 22.0MB bios_grub bios_grub
3 1322MB 2371MB 1049MB fat32 Basic data partition hidden
4 2371MB 2505MB 134MB Microsoft reserved partition msftres
5 2505MB 102GB 99.6GB ntfs Basic data partition msftdata
6 102GB 103GB 367MB ntfs hidden, diag
7 103GB 153GB 50.0GB ext4 msftdata
8 153GB 693GB 540GB ext4 msftdata
9 693GB 702GB 9032MB linux-swap(v1)
10 702GB 729GB 26.8GB ntfs Basic data partition msftdata
11 729GB 750GB 21.5GB ntfs Basic data partition hidden, diag
and all I had to do was install the GRUB bootloader to /dev/sdb and
everything worked!