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.
/usr/lib/systemd/system-generators/systemd-gpt-auto-generator
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. Note that this generator has no
effect on non-GPT systems, on systems where the units are
explicitly configured (for example, listed in
fstab(5)),
or where the mount points are non-empty.
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 ARM) | On 32-bit ARM systems, 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 ARM) | On 64-bit ARM systems, the first ARM 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. |
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.
Also note that
systemd-efi-boot-generator(8)
will mount the EFI System Partition (ESP) to
/boot if not otherwise mounted.
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
the
Generator
Specification.