Installing on GPT LVM

This is an updated version of this Howto: Setting up LVM on GPT-labeled disks.

This document describes how to set up a system booting from a logical volume in Alpine Linux using lvm2 and GPT-labeled disks.

Begin by booting from Alpine Linux installation media in the usual way. Log in as `root`, run `setup-alpine`, and answer `none` when asked to choose a disk.

Info

Alpine Linux ISO used in this installation: alpine-vanilla-3.7.0-x86_64.iso

This PC has BIOS, not UEFI (UEFI installation may differ)

Tested on APU4C with 30GB Kingston mSata SSD (SMS200S3/30G).

Partitioning

We need to install some tools, as 'gptfdisk' and 'sgdisk' are part of main.

Install gptfdisk.

apk add -U gptfdisk sgdisk

Create some partitions. In my case the SSD disk is found as sda, so I will use 'sda' throughout the process.

gdisk /dev/sda

# create a new empty GUID partition table (GPT) with 'o'
o # then 'y' to confirm
# create some partitions: BIOS (needed only for GRUB2), Boot (needed by SYSLINUX), and LVM
n
1
<enter>
+2M
ef02
n
2
<enter>
+100M
8300
n
3
<enter>
<enter>
8e00
# print the partition table with 'p'

You should get something like this:

Number  Start (sector)    End (sector)  Size       Code  Name
  1            2048            6143   2.0 MiB     EF02  BIOS boot partition
  2            6144          210943   100.0 MiB   8300  Linux filesystem
  3          210944        15662270   7.4 GiB     8E00  Linux LVM

We need to set the 'legacy BIOS bootable' flag on our boot partition, which can be done in gdisk by first entering expert mode with 'x' then editing attributes with 'a'. It's used by SYSLINUX's GPT support to identify a partition that holds second-stage boot code.

x
a
2
2

It looks like this:

Command (? for help): x

Expert command (? for help): a
Partition number (1-3): 2
Known attributes are:
0: system partition
1: hide from EFI
2: legacy BIOS bootable
60: read-only
62: hidden
63: do not automount

Attribute value is 0000000000000000. Set fields are:
 No fields set

Toggle which attribute field (0-63, 64 or <Enter> to exit): 2
Have enabled the 'legacy BIOS bootable' attribute.
Attribute value is 0000000000000004. Set fields are:
2 (legacy BIOS bootable)

Press 'Enter' to exit the expert mode and then write table to disk and exit gdisk with 'w'.

You can verify the legacy_boot flag with sgdisk (also part of the gptfdisk).

sgdisk /dev/sda --attributes=1:show

sgdisk /dev/sda --attributes=2:show

2:2:1 (legacy BIOS bootable)

sgdisk /dev/sda --attributes=3:show

Remove gptfdisk (if not needed anymore).

apk del gptfdisk sgdisk

LVM Setup

Now we can setup LVM on the third partition created in the process above.

apk add lvm2 e2fsprogs syslinux

pvcreate /dev/sda3

 Physical volume "/dev/sda3" successfully created

vgcreate vg00 /dev/sda3

 Volume group "vg00" successfully created

lvcreate -n alpine_rootfs -L4G vg00

 Logical volume "alpine_rootfs" created

lvcreate -n swap -C y -L 512M vg00

 Logical volume "swap" created

rc-update add lvm

* service lvm added to runlevel default

vgchange -ay

 2 logical volume(s) in volume group "vg00" now active

Format new logical volume and activate swap.

mkfs.ext3 /dev/sda2

mkfs.ext4 /dev/vg00/alpine_rootfs

mkswap /dev/vg0/swap

Mount for finishing Alpine Linux installation.

mount -t ext4 /dev/vg00/alpine_rootfs /mnt

mkdir /mnt/boot

mount -t ext3 /dev/sda2 /mnt/boot

Finish installation

Run this command to finish installing Alpine Linux to our newly mounted partition on /mnt:

setup-disk -m sys /mnt

Output of setup-disk should be like this:

Installing system on /dev/vg00/alpine_rootfs:
/mnt/boot is device /dev/sda2
/boot is device /dev/sda2
You might need fix the MBR to be able to boot

Syslinux

Install the MBR.

dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/gptmbr.bin of=/dev/sda

Reboot and enjoy your new Alpine Linux installation!