From 55944e5e40b1be2afc4855d8d2baf4b73d1876b5 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 10 Apr 2024 22:49:52 +0200 Subject: Adding upstream version 255.4. Signed-off-by: Daniel Baumann --- man/systemd-gpt-auto-generator.xml | 329 +++++++++++++++++++++++++++++++++++++ 1 file changed, 329 insertions(+) create mode 100644 man/systemd-gpt-auto-generator.xml (limited to 'man/systemd-gpt-auto-generator.xml') diff --git a/man/systemd-gpt-auto-generator.xml b/man/systemd-gpt-auto-generator.xml new file mode 100644 index 0000000..db51076 --- /dev/null +++ b/man/systemd-gpt-auto-generator.xml @@ -0,0 +1,329 @@ + + + + + + + + systemd-gpt-auto-generator + systemd + + + + systemd-gpt-auto-generator + 8 + + + + systemd-gpt-auto-generator + Generator for automatically discovering and mounting root, /home/, + /srv/, /var/ and /var/tmp/ partitions, as + well as discovering and enabling swap partitions, based on GPT partition type GUIDs + + + + /usr/lib/systemd/system-generators/systemd-gpt-auto-generator + + + + Description + + systemd-gpt-auto-generator is a unit generator that automatically discovers + the root partition, /home/, /srv/, /var/, + /var/tmp/, the EFI System Partition, the Extended Boot Loader Partition, and swap + partitions and creates mount and swap units for them, based on the partition type GUIDs of GUID partition + tables (GPT). See UEFI Specification, chapter 5 for + more details. It implements the Discoverable + Partitions Specification. + + Note that this generator has no effect on non-GPT systems. It will also not create mount point + configuration for directories which already contain files or if the mount point is explicitly configured + in fstab5. If + the units this generator creates are overridden, for example by units in directories with higher + precedence, drop-ins and additional dependencies created by this generator might still be used. + + This generator will only look for the root partition on the same physical disk where the EFI System + Partition (ESP) is located. Note that support from the boot loader is required: the EFI variable + LoaderDevicePartUUID of the 4a67b082-0a4c-41cf-b6c7-440b29bb8c4f + vendor UUID is used to determine from which partition, and hence the disk, from which the system was + booted. If the boot loader does not set this variable, this generator will not be able to detect the root + partition. See the Boot Loader Interface + for details. + + Similarly, this generator will only look for the other partitions on the same physical disk as the + root partition. In this case, boot loader support is not required. These partitions will not be searched + for 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 configuration in /etc/fstab or on + the kernel command line unnecessary. + + This generator looks for the partitions based on their + partition type GUID. The following partition type GUIDs are + identified: + + + Partition Type GUIDs + + + + + + + + Partition Type GUID + Name + Mount Point + Explanation + + + + + SD_GPT_ROOT_X86_64 4f68bce3-e8cd-4db1-96e7-fbcaf984b709 + Root Partition (x86-64) + / + The first partition with this type UUID, located on the same disk as the ESP, is used as the root file system / on AMD64 / 64-bit x86 systems. + + + SD_GPT_ROOT_ARM64 b921b045-1df0-41c3-af44-4c6f280d3fae + Root Partition (64-bit ARM) + / + The first partition with this type UUID, located on the same disk as the ESP, is used as the root file system / on AArch64 / 64-bit ARM systems. + + + + SD_GPT_ROOT_ALPHA SD_GPT_ROOT_ARC SD_GPT_ROOT_ARM SD_GPT_ROOT_ARM64 SD_GPT_ROOT_IA64 SD_GPT_ROOT_LOONGARCH64 SD_GPT_ROOT_MIPS SD_GPT_ROOT_MIPS64 SD_GPT_ROOT_MIPS_LE SD_GPT_ROOT_MIPS64_LE SD_GPT_ROOT_PARISC SD_GPT_ROOT_PPC SD_GPT_ROOT_PPC64 SD_GPT_ROOT_PPC64_LE SD_GPT_ROOT_RISCV32 SD_GPT_ROOT_RISCV64 SD_GPT_ROOT_S390 SD_GPT_ROOT_S390X SD_GPT_ROOT_TILEGX SD_GPT_ROOT_X86 SD_GPT_ROOT_X86_64 SD_GPT_USR_ALPHA SD_GPT_USR_ARC SD_GPT_USR_ARM SD_GPT_USR_IA64 SD_GPT_USR_LOONGARCH64 SD_GPT_USR_MIPS_LE SD_GPT_USR_MIPS64_LE SD_GPT_USR_PARISC SD_GPT_USR_PPC SD_GPT_USR_PPC64 SD_GPT_USR_PPC64_LE SD_GPT_USR_RISCV32 SD_GPT_USR_RISCV64 SD_GPT_USR_S390 SD_GPT_USR_S390X SD_GPT_USR_TILEGX SD_GPT_USR_X86 + + root partitions for other architectures + / + The first partition with the type UUID matching the architecture, located on the same disk as the ESP, is used as the root file system /. For the full list and constant values, see Discoverable Partitions Specification. + + + SD_GPT_HOME 933ac7e1-2eb4-4f13-b844-0e14e2aef915 + Home Partition + /home/ + The first partition with this type UUID on the same disk as the ESP is mounted to /home/. + + + SD_GPT_SRV 3b8f8425-20e0-4f3b-907f-1a25a76f98e8 + Server Data Partition + /srv/ + The first partition with this type UUID on the same disk as the ESP is mounted to /srv/. + + + SD_GPT_VAR 4d21b016-b534-45c2-a9fb-5c16e091fd2d + Variable Data Partition + /var/ + The first partition with this type UUID on the same disk as the ESP is mounted to /var/ — under the condition its partition UUID matches the first 128 bit of the HMAC-SHA256 of the GPT type uuid of this partition keyed by the machine ID of the installation stored in machine-id5. + + + SD_GPT_TMP 7ec6f557-3bc5-4aca-b293-16ef5df639d1 + Temporary Data Partition + /var/tmp/ + The first partition with this type UUID on the same disk as the ESP is mounted to /var/tmp/. + + + SD_GPT_SWAP 0657fd6d-a4ab-43c4-84e5-0933c84b4f4f + Swap + n/a + All partitions with this type UUID on the same disk as the ESP are used as swap. + + + SD_GPT_ESP c12a7328-f81f-11d2-ba4b-00a0c93ec93b + EFI System Partition (ESP) + /efi/ or /boot/ + The first partition with this type UUID located on the same disk as the root partition is mounted to /boot/ or /efi/, see below. + + + SD_GPT_XBOOTLDR bc13c2ff-59e6-4262-a352-b275fd6f7172 + Extended Boot Loader Partition + /boot/ + The first partition with this type UUID located on the same disk as the root partition is mounted to /boot/, see below. + + + +
+ + This generator understands the following attribute flags for partitions: + + + Partition Attribute Flags + + + + + + + Flag + Applicable to + Explanation + + + + + SD_GPT_FLAG_READ_ONLY 0x1000000000000000 + /, /home/, /srv/, /var/, /var/tmp/, Extended Boot Loader Partition + Partition is mounted read-only + + + + SD_GPT_FLAG_NO_AUTO 0x8000000000000000 + /, /home/, /srv/, /var/, /var/tmp/, Extended Boot Loader Partition + Partition is not mounted automatically + + + + SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL 0x0000000000000002 + EFI System Partition (ESP) + Partition is not mounted automatically + + + +
+ + The /home/, /srv/, /var/, + /var/tmp/ and swap partitions may be encrypted in LUKS format. In this case, a + device mapper device is set up under the names /dev/mapper/home, + /dev/mapper/srv, /dev/mapper/var, + /dev/mapper/tmp or /dev/mapper/swap. Note that this might + create conflicts if the same partition is listed in /etc/crypttab with a different + device mapper device name. + + When systemd is running in the initrd the / partition may be encrypted with + LUKS as well. In this case, a device mapper device is set up under the name + /dev/mapper/root, and a sysroot.mount is set up that mounts the + device under /sysroot. For more information, see + bootup7. + + + The root partition can be specified by symlinking /run/systemd/volatile-root + to /dev/block/$major:$minor. This is especially useful if the root mount has been + replaced by some form of volatile file system (overlayfs). + + + Mount and automount units for the EFI System Partition (ESP) and Extended Boot Loader Partition + (XBOOTLDR) are generated on EFI systems. If the disk contains an XBOOTLDR partition, as defined in the + Boot Loader + Specification, it is made available at /boot/. This generator creates an + automount unit; the mount will only be activated on-demand when accessed. The mount point will be created + if necessary. + + The ESP is mounted to /boot/ if that directory exists and is not used for + XBOOTLDR, and otherwise to /efi/. Same as for /boot/, an + automount unit is used. The mount point will be created if necessary. + + No configuration is created for mount points that are configured in fstab5 or when + the target directory contains files. + + 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. + + If the system was booted via + systemd-stub7 and the + stub reported to userspace that the kernel image was measured to a TPM2 PCR, then any discovered root and + /var/ volume identifiers (and volume encryption key in case it is encrypted) will be + automatically measured into PCR 15 on activation, via + systemd-pcrfs@.service8. + + systemd-gpt-auto-generator implements + systemd.generator7. + + + + Kernel Command Line + + systemd-gpt-auto-generator understands the following kernel command line + parameters: + + + + + systemd.gpt_auto + rd.systemd.gpt_auto + + Those options take an optional boolean argument, and default to yes. + The generator is enabled by default, and a false value may be used to disable it + (e.g. systemd.gpt_auto=0). + + + + + + + systemd.image_policy= + rd.systemd.image_policy= + + Takes an image dissection policy string as argument (as per + systemd.image-policy7), + and allows enforcing a policy on dissection and use of the automatically discovered GPT partition + table entries. + + + + + + root= + rootfstype= + rootflags= + + When root= is used with the special value + gpt-auto (or if the parameter is not used at all), automatic discovery of the root + partition based on the GPT partition type is enabled. Any other value disables this + logic. + + The rootfstype= and rootflags= are used to select the + file system type and options when the root file system is automatically discovered. + + + + + + rw + ro + + Mount the root partition read-write or read-only initially. + + Note that unlike most kernel command line options these settings do not override configuration + in the file system, and the file system may be remounted later. See + systemd-remount-fs.service8. + + + + + + + systemd.swap= + + Takes a boolean argument or enables the option if specified without an argument. + If disabled, automatic discovery of swap partition(s) based on GPT partition type is disabled. + Defaults to enabled. + + + + + + + + See Also + + systemd1, + systemd.mount5, + systemd.swap5, + systemd-fstab-generator8, + systemd-cryptsetup@.service8, + systemd-pcrfs@.service8, + machine-id5, + cryptsetup8, + fstab5, + btrfs8 + + + + -- cgit v1.2.3