Provided by: systemd_237-3ubuntu10.57_amd64 
NAME
systemd-gpt-auto-generator - Generator for automatically discovering and mounting root,
/home and /srv partitions, as well as discovering and enabling swap partitions, based on
GPT partition type GUIDs.
SYNOPSIS
/lib/systemd/system-generators/systemd-gpt-auto-generator
DESCRIPTION
systemd-gpt-auto-generator is a unit generator that automatically discovers root, /home,
/srv and swap partitions and creates mount and swap units for them, based on the partition
type GUIDs of GUID partition tables (GPT). It implements the Discoverable Partitions
Specification[1]. Note that this generator has no effect on non-GPT systems, or where the
directories under the mount points are already non-empty. Also, on systems where the units
are explicitly configured (for example, listed in fstab(5)), the units this generator
creates are overridden, but additional implicit dependencies might be created.
This generator will only look for root partitions on the same physical disk the EFI System
Partition (ESP) is located on. It will only look for the other partitions on the same
physical disk the root file system is located on. These partitions will not be searched on
systems where the root file system is distributed on multiple disks, for example via btrfs
RAID.
systemd-gpt-auto-generator is useful for centralizing file system configuration in the
partition table and making manual configuration in /etc/fstab or suchlike unnecessary.
This generator looks for the partitions based on their partition type GUID. The following
partition type GUIDs are identified:
Table 1. Partition Type GUIDs
┌─────────────────────────────────────┬─────────────────────────┬──────────────────────────┐
│Partition Type GUID │ Name │ Explanation │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│44479540-f297-41b2-9af7-d131d5f0458a │ Root Partition (x86) │ On 32-bit x86 systems, │
│ │ │ the first x86 root │
│ │ │ partition on the disk │
│ │ │ the EFI ESP is located │
│ │ │ on is mounted to the │
│ │ │ root directory /. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│4f68bce3-e8cd-4db1-96e7-fbcaf984b709 │ Root Partition (x86-64) │ On 64-bit x86 systems, │
│ │ │ the first x86-64 root │
│ │ │ partition on the disk │
│ │ │ the EFI ESP is located │
│ │ │ on is mounted to the │
│ │ │ root directory /. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│69dad710-2ce4-4e3c-b16c-21a1d49abed3 │ Root Partition (32-bit │ On 32-bit ARM systems, │
│ │ ARM) │ the first ARM root │
│ │ │ partition on the disk │
│ │ │ the EFI ESP is located │
│ │ │ on is mounted to the │
│ │ │ root directory /. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│b921b045-1df0-41c3-af44-4c6f280d3fae │ Root Partition (64-bit │ On 64-bit ARM systems, │
│ │ ARM) │ the first ARM root │
│ │ │ partition on the disk │
│ │ │ the EFI ESP is located │
│ │ │ on is mounted to the │
│ │ │ root directory /. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│993d8d3d-f80e-4225-855a-9daf8ed7ea97 │ Root Partition │ On Itanium systems, the │
│ │ (Itanium/IA-64) │ first Itanium root │
│ │ │ partition on the disk │
│ │ │ the EFI ESP is located │
│ │ │ on is mounted to the │
│ │ │ root directory /. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│933ac7e1-2eb4-4f13-b844-0e14e2aef915 │ Home Partition │ The first home partition │
│ │ │ on the disk the root │
│ │ │ partition is located on │
│ │ │ is mounted to /home. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│3b8f8425-20e0-4f3b-907f-1a25a76f98e8 │ Server Data Partition │ The first server data │
│ │ │ partition on the disk │
│ │ │ the root partition is │
│ │ │ located on is mounted to │
│ │ │ /srv. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│0657fd6d-a4ab-43c4-84e5-0933c84b4f4f │ Swap │ All swap partitions │
│ │ │ located on the disk the │
│ │ │ root partition is │
│ │ │ located on are enabled. │
├─────────────────────────────────────┼─────────────────────────┼──────────────────────────┤
│c12a7328-f81f-11d2-ba4b-00a0c93ec93b │ EFI System Partition │ The first ESP located on │
│ │ (ESP) │ the disk the root │
│ │ │ partition is located on │
│ │ │ is mounted to /boot or │
│ │ │ /efi, see below. │
└─────────────────────────────────────┴─────────────────────────┴──────────────────────────┘
The /home and /srv partitions may be encrypted in LUKS format. In this case, a device
mapper device is set up under the names /dev/mapper/home and /dev/mapper/srv. Note that
this might create conflicts if the same partition is listed in /etc/crypttab with a
different device mapper device name.
Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems.
The ESP is mounted to /boot, unless a mount point directory /efi exists, in which case it
is mounted there. Since this generator creates an automount unit, the mount will only be
activated on-demand, when accessed. On systems where /boot (or /efi if it exists) is an
explicitly configured mount (for example, listed in fstab(5)) or where the /boot (or /efi)
mount point is non-empty, no mount units are generated.
When using this generator in conjunction with btrfs file systems, make sure to set the
correct default subvolumes on them, using btrfs subvolume set-default.
systemd-gpt-auto-generator implements systemd.generator(7).
SEE ALSO
systemd(1), systemd.mount(5), systemd.swap(5), systemd-fstab-generator(8), systemd-
cryptsetup@.service(8), cryptsetup(8), fstab(5), btrfs(8)
NOTES
1. Discoverable Partitions Specification
https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/