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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

/usr/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. 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 GUIDNameExplanation
44479540-f297-41b2-9af7-d131d5f0458aRoot 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-fbcaf984b709Root 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-21a1d49abed3Root 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-af44-4c6f280d3faeRoot 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-b844-0e14e2aef915Home PartitionThe first home partition on the disk the root partition is located on is mounted to /home.
3b8f8425-20e0-4f3b-907f-1a25a76f98e8Server Data PartitionThe first server data partition on the disk the root partition is located on is mounted to /srv.
0657fd6d-a4ab-43c4-84e5-0933c84b4f4fSwapAll 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.

See Also

systemd(1), systemd.mount(5), systemd.swap(5), systemd-fstab-generator(8), systemd-efi-boot-generator(8), systemd-cryptsetup@.service(8), cryptsetup(8), fstab(5), btrfs(8)