1SYSTEMD-GPT-AUTO-GENERATOR(s8y)stemd-gpt-auto-generatSoYrSTEMD-GPT-AUTO-GENERATOR(8)
2
6 systemd-gpt-auto-generator - Generator for automatically discovering
7 and mounting root, /home and /srv partitions, as well as discovering
8 and enabling swap partitions, based on GPT partition type GUIDs.
9
11 /usr/lib/systemd/system-generators/systemd-gpt-auto-generator
12
14 systemd-gpt-auto-generator is a unit generator that automatically
15 discovers root, /home, /srv and swap partitions and creates mount and
16 swap units for them, based on the partition type GUIDs of GUID
17 partition tables (GPT), see UEFI Specification[1], chapter 5. It
18 implements the Discoverable Partitions Specification[2]. Note that this
19 generator has no effect on non-GPT systems, or where the directories
20 under the mount points are already non-empty. Also, on systems where
21 the units are explicitly configured (for example, listed in fstab(5)),
22 the units this generator creates are overridden, but additional
23 implicit dependencies might be created.
24 This generator will only look for root partitions on the same physical
26 disk the EFI System Partition (ESP) is located on. It will only look
27 for the other partitions on the same physical disk the root file system
28 is located on. These partitions will not be searched for on systems
29 where the root file system is distributed on multiple disks, for
30 example via btrfs RAID.
31 systemd-gpt-auto-generator is useful for centralizing file system
33 configuration in the partition table and making configuration in
34 /etc/fstab unnecessary.
35 This generator looks for the partitions based on their partition type
37 GUID. The following partition type GUIDs are identified:
38 Table 1. Partition Type GUIDs
40 ┌─────────────────────────────────────┬─────────────────┬─────────────────────┐
41 │Partition Type GUID │ Name │ Explanation │
42 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
43 │44479540-f297-41b2-9af7-d131d5f0458a │ Root Partition │ On 32-bit x86 │
44 │ │ (x86) │ systems, the first │
45 │ │ │ x86 root partition │
46 │ │ │ on the disk the EFI │
47 │ │ │ ESP is located on │
48 │ │ │ is mounted to the │
49 │ │ │ root directory /. │
50 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
51 │4f68bce3-e8cd-4db1-96e7-fbcaf984b709 │ Root Partition │ On 64-bit x86 │
52 │ │ (x86-64) │ systems, the first │
53 │ │ │ x86-64 root │
54 │ │ │ partition on the │
55 │ │ │ disk the EFI ESP is │
56 │ │ │ located on is │
57 │ │ │ mounted to the root │
58 │ │ │ directory /. │
59 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
60 │69dad710-2ce4-4e3c-b16c-21a1d49abed3 │ Root Partition │ On 32-bit ARM │
61 │ │ (32-bit ARM) │ systems, the first │
62 │ │ │ ARM root partition │
63 │ │ │ on the disk the EFI │
64 │ │ │ ESP is located on │
65 │ │ │ is mounted to the │
66 │ │ │ root directory /. │
67 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
68 │b921b045-1df0-41c3-af44-4c6f280d3fae │ Root Partition │ On 64-bit ARM │
69 │ │ (64-bit ARM) │ systems, the first │
70 │ │ │ ARM root partition │
71 │ │ │ on the disk the EFI │
72 │ │ │ ESP is located on │
73 │ │ │ is mounted to the │
74 │ │ │ root directory /. │
75 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
76 │993d8d3d-f80e-4225-855a-9daf8ed7ea97 │ Root Partition │ On Itanium systems, │
77 │ │ (Itanium/IA-64) │ the first Itanium │
78 │ │ │ root partition on │
79 │ │ │ the disk the EFI │
80 │ │ │ ESP is located on │
81 │ │ │ is mounted to the │
82 │ │ │ root directory /. │
83 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
84 │933ac7e1-2eb4-4f13-b844-0e14e2aef915 │ Home Partition │ The first home │
85 │ │ │ partition on the │
86 │ │ │ disk the root │
87 │ │ │ partition is │
88 │ │ │ located on is │
89 │ │ │ mounted to /home. │
90 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
91 │3b8f8425-20e0-4f3b-907f-1a25a76f98e8 │ Server Data │ The first server │
92 │ │ Partition │ data partition on │
93 │ │ │ the disk the root │
94 │ │ │ partition is │
95 │ │ │ located on is │
96 │ │ │ mounted to /srv. │
97 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
98 │0657fd6d-a4ab-43c4-84e5-0933c84b4f4f │ Swap │ All swap partitions │
99 │ │ │ located on the disk │
100 │ │ │ the root partition │
101 │ │ │ is located on are │
102 │ │ │ enabled. │
103 ├─────────────────────────────────────┼─────────────────┼─────────────────────┤
104 │c12a7328-f81f-11d2-ba4b-00a0c93ec93b │ EFI System │ The first ESP │
105 │ │ Partition (ESP) │ located on the disk │
106 │ │ │ the root partition │
107 │ │ │ is located on is │
108 │ │ │ mounted to /boot or │
109 │ │ │ /efi, see below. │
110 └─────────────────────────────────────┴─────────────────┴─────────────────────┘
111 This generator understands the following attribute flags for
113 partitions:
114 Table 2. Partition Attributes
116 ┌──────────────────────────────┬────────────────────┬────────────────┬──────────────────┐
117 │Name │ Value │ Applicable to │ Explanation │
118 ├──────────────────────────────┼────────────────────┼────────────────┼──────────────────┤
119 │GPT_FLAG_READ_ONLY │ 0x1000000000000000 │ /, /srv, /home │ Partition is │
120 │ │ │ │ mounted │
121 │ │ │ │ read-only │
122 ├──────────────────────────────┼────────────────────┼────────────────┼──────────────────┤
123 │GPT_FLAG_NO_AUTO │ 0x8000000000000000 │ /, /srv, /home │ Partition is not │
124 │ │ │ │ mounted │
125 │ │ │ │ automatically │
126 ├──────────────────────────────┼────────────────────┼────────────────┼──────────────────┤
127 │GPT_FLAG_NO_BLOCK_IO_PROTOCOL │ 0x0000000000000002 │ ESP │ Partition is not │
128 │ │ │ │ mounted │
129 │ │ │ │ automatically │
130 └──────────────────────────────┴────────────────────┴────────────────┴──────────────────┘
131 The /home and /srv partitions may be encrypted in LUKS format. In this
133 case, a device mapper device is set up under the names /dev/mapper/home
134 and /dev/mapper/srv. Note that this might create conflicts if the same
135 partition is listed in /etc/crypttab with a different device mapper
136 device name.
137 Mount and automount units for the EFI System Partition (ESP) are
139 generated on EFI systems. The ESP is mounted to /boot, unless a mount
140 point directory /efi exists, in which case it is mounted there. Since
141 this generator creates an automount unit, the mount will only be
142 activated on-demand, when accessed. On systems where /boot (or /efi if
143 it exists) is an explicitly configured mount (for example, listed in
144 fstab(5)) or where the /boot (or /efi) mount point is non-empty, no
145 mount units are generated.
146 When using this generator in conjunction with btrfs file systems, make
148 sure to set the correct default subvolumes on them, using btrfs
149 subvolume set-default.
150 systemd-gpt-auto-generator implements systemd.generator(7).
152
154 systemd(1), systemd.mount(5), systemd.swap(5), systemd-fstab-
155 generator(8), systemd-cryptsetup@.service(8), cryptsetup(8), fstab(5),
156 btrfs(8)
157
159 1. UEFI Specification
160 http://www.uefi.org/specifications
161 2. Discoverable Partitions Specification
163 https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/
164systemd 239 SYSTEMD-GPT-AUTO-GENERATOR(8)