]>
Commit | Line | Data |
---|---|---|
69055103 TL |
1 | [[sysboot]] |
2 | Host Bootloader | |
3 | --------------- | |
62de1c14 SI |
4 | ifdef::wiki[] |
5 | :pve-toplevel: | |
6 | endif::wiki[] | |
7 | ||
69055103 TL |
8 | {pve} currently uses one of two bootloaders depending on the disk setup |
9 | selected in the installer. | |
62de1c14 SI |
10 | |
11 | For EFI Systems installed with ZFS as the root filesystem `systemd-boot` is | |
12 | used. All other deployments use the standard `grub` bootloader (this usually | |
13 | also applies to systems which are installed on top of Debian). | |
14 | ||
69055103 | 15 | [[sysboot_installer_part_scheme]] |
62de1c14 SI |
16 | Partitioning scheme used by the installer |
17 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
18 | ||
19 | The {pve} installer creates 3 partitions on the bootable disks selected for | |
20 | installation. The bootable disks are: | |
21 | ||
22 | * For Installations with `ext4` or `xfs` the selected disk | |
23 | ||
24 | * For ZFS installations all disks belonging to the first `vdev`: | |
25 | ** The first disk for RAID0 | |
26 | ** All disks for RAID1, RAIDZ1, RAIDZ2, RAIDZ3 | |
27 | ** The first two disks for RAID10 | |
28 | ||
29 | The created partitions are: | |
30 | ||
31 | * a 1 MB BIOS Boot Partition (gdisk type EF02) | |
32 | ||
33 | * a 512 MB EFI System Partition (ESP, gdisk type EF00) | |
34 | ||
35 | * a third partition spanning the set `hdsize` parameter or the remaining space | |
36 | used for the chosen storage type | |
37 | ||
38 | `grub` in BIOS mode (`--target i386-pc`) is installed onto the BIOS Boot | |
39 | Partition of all bootable disks for supporting older systems. | |
40 | ||
41 | ||
69055103 | 42 | [[sysboot_grub]] |
62de1c14 SI |
43 | Grub |
44 | ~~~~ | |
45 | ||
46 | `grub` has been the de-facto standard for booting Linux systems for many years | |
47 | and is quite well documented | |
48 | footnote:[Grub Manual https://www.gnu.org/software/grub/manual/grub/grub.html]. | |
49 | ||
50 | The kernel and initrd images are taken from `/boot` and its configuration file | |
51 | `/boot/grub/grub.cfg` gets updated by the kernel installation process. | |
52 | ||
53 | Configuration | |
54 | ^^^^^^^^^^^^^ | |
55 | Changes to the `grub` configuration are done via the defaults file | |
56 | `/etc/default/grub` or config snippets in `/etc/default/grub.d`. To regenerate | |
57 | the `/boot/grub/grub.cfg` after a change to the configuration run: | |
58 | ||
59 | ---- | |
60 | `update-grub`. | |
61 | ---- | |
62 | ||
69055103 | 63 | [[sysboot_systemd_boot]] |
62de1c14 SI |
64 | Systemd-boot |
65 | ~~~~~~~~~~~~ | |
66 | ||
67 | `systemd-boot` is a lightweight EFI bootloader. It reads the kernel and initrd | |
68 | images directly from the EFI Service Partition (ESP) where it is installed. | |
69 | The main advantage of directly loading the kernel from the ESP is that it does | |
70 | not need to reimplement the drivers for accessing the storage. In the context | |
71 | of ZFS as root filesystem this means that you can use all optional features on | |
72 | your root pool instead of the subset which is also present in the ZFS | |
73 | implementation in `grub` or having to create a separate small boot-pool | |
74 | footnote:[Booting ZFS on root with grub https://github.com/zfsonlinux/zfs/wiki/Debian-Stretch-Root-on-ZFS]. | |
75 | ||
76 | In setups with redundancy (RAID1, RAID10, RAIDZ*) all bootable disks (those | |
77 | being part of the first `vdev`) are partitioned with an ESP. This ensures the | |
78 | system boots even if the first boot device fails. The ESPs are kept in sync by | |
79 | a kernel postinstall hook script `/etc/kernel/postinst.d/zz-pve-efiboot`. The | |
80 | script copies certain kernel versions and the initrd images to `EFI/proxmox/` | |
81 | on the root of each ESP and creates the appropriate config files in | |
300655b3 FG |
82 | `loader/entries/proxmox-*.conf`. The `pve-efiboot-tool` script assists in |
83 | managing both the synced ESPs themselves and their contents. | |
62de1c14 SI |
84 | |
85 | The following kernel versions are configured by default: | |
86 | ||
87 | * the currently running kernel | |
88 | * the version being newly installed on package updates | |
8152d9b6 FG |
89 | * the two latest already installed kernels |
90 | * the latest version of the second-to-last kernel series (e.g. 4.15, 5.0), if applicable | |
91 | * any manually selected kernels (see below) | |
62de1c14 SI |
92 | |
93 | The ESPs are not kept mounted during regular operation, in contrast to `grub`, | |
94 | which keeps an ESP mounted on `/boot/efi`. This helps to prevent filesystem | |
95 | corruption to the `vfat` formatted ESPs in case of a system crash, and removes | |
96 | the need to manually adapt `/etc/fstab` in case the primary boot device fails. | |
97 | ||
69055103 | 98 | [[sysboot_systemd_boot_config]] |
62de1c14 SI |
99 | Configuration |
100 | ^^^^^^^^^^^^^ | |
101 | ||
102 | `systemd-boot` is configured via the file `loader/loader.conf` in the root | |
103 | directory of an EFI System Partition (ESP). See the `loader.conf(5)` manpage | |
104 | for details. | |
105 | ||
106 | Each bootloader entry is placed in a file of its own in the directory | |
107 | `loader/entries/` | |
108 | ||
109 | An example entry.conf looks like this (`/` refers to the root of the ESP): | |
110 | ||
111 | ---- | |
112 | title Proxmox | |
113 | version 5.0.15-1-pve | |
114 | options root=ZFS=rpool/ROOT/pve-1 boot=zfs | |
115 | linux /EFI/proxmox/5.0.15-1-pve/vmlinuz-5.0.15-1-pve | |
116 | initrd /EFI/proxmox/5.0.15-1-pve/initrd.img-5.0.15-1-pve | |
117 | ---- | |
118 | ||
119 | ||
120 | .Manually keeping a kernel bootable | |
121 | ||
122 | Should you wish to add a certain kernel and initrd image to the list of | |
f11fb629 | 123 | bootable kernels use `pve-efiboot-tool kernel add`. |
62de1c14 | 124 | |
1722c45b FG |
125 | For example run the following to add the kernel with ABI version `5.0.15-1-pve` |
126 | to the list of kernels to keep installed and synced to all ESPs: | |
62de1c14 | 127 | |
1722c45b FG |
128 | ---- |
129 | pve-efiboot-tool kernel add 5.0.15-1-pve | |
130 | ---- | |
131 | ||
132 | `pve-efiboot-tool kernel list` will list all kernel versions currently selected | |
133 | for booting: | |
134 | ||
135 | ---- | |
136 | # pve-efiboot-tool kernel list | |
137 | Manually selected kernels: | |
138 | 5.0.15-1-pve | |
139 | ||
140 | Automatically selected kernels: | |
141 | 5.0.12-1-pve | |
142 | 4.15.18-18-pve | |
143 | ---- | |
62de1c14 | 144 | |
1722c45b FG |
145 | Run `pve-efiboot-tool remove` to remove a kernel from the list of manually |
146 | selected kernels, for example: | |
62de1c14 SI |
147 | |
148 | ---- | |
1722c45b | 149 | pve-efiboot-tool kernel remove 5.0.15-1-pve |
62de1c14 SI |
150 | ---- |
151 | ||
b74373e4 TL |
152 | NOTE: It's required to run `pve-efiboot-tool refresh` to update all EFI System |
153 | Partitions (ESPs) after a manual kernel addition or removal from above. | |
1722c45b | 154 | |
0daaddbd FG |
155 | [[sysboot_systemd_boot_setup]] |
156 | .Setting up a new partition for use as synced ESP | |
157 | ||
158 | To format and initialize a partition as synced ESP, e.g., after replacing a | |
159 | failed vdev in an rpool, or when converting an existing system that pre-dates | |
160 | the sync mechanism, `pve-efiboot-tool` from `pve-kernel-helpers` can be used. | |
161 | ||
162 | WARNING: the `format` command will format the `<partition>`, make sure to pass | |
163 | in the right device/partition! | |
164 | ||
165 | For example, to format an empty partition `/dev/sda2` as ESP, run the following: | |
166 | ||
167 | ---- | |
168 | pve-efiboot-tool format /dev/sda2 | |
169 | ---- | |
170 | ||
171 | To setup an existing, unmounted ESP located on `/dev/sda2` for inclusion in | |
3fe127c7 | 172 | {pve}'s kernel update synchronization mechanism, use the following: |
0daaddbd FG |
173 | |
174 | ---- | |
175 | pve-efiboot-tool init /dev/sda2 | |
176 | ---- | |
177 | ||
178 | Afterwards `/etc/kernel/pve-efiboot-uuids` should contain a new line with the | |
179 | UUID of the newly added partition. The `init` command will also automatically | |
180 | trigger a refresh of all configured ESPs. | |
62de1c14 | 181 | |
69055103 | 182 | [[sysboot_systemd_boot_refresh]] |
62de1c14 SI |
183 | .Updating the configuration on all ESPs |
184 | ||
0daaddbd | 185 | To copy and configure all bootable kernels and keep all ESPs listed in |
b74373e4 TL |
186 | `/etc/kernel/pve-efiboot-uuids` in sync you just need to run: |
187 | ||
188 | ---- | |
189 | pve-efiboot-tool refresh | |
190 | ---- | |
f11fb629 | 191 | (The equivalent to running `update-grub` on systems being booted with `grub`). |
62de1c14 | 192 | |
0daaddbd | 193 | This is necessary should you make changes to the kernel commandline, or want to |
0aebb0d9 SR |
194 | sync all kernels and initrds. |
195 | ||
196 | NOTE: Both `update-initramfs` and `apt` (when necessary) will automatically | |
197 | trigger a refresh. | |
62de1c14 | 198 | |
69055103 | 199 | [[sysboot_edit_kernel_cmdline]] |
62de1c14 SI |
200 | Editing the kernel commandline |
201 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
202 | ||
203 | You can modify the kernel commandline in the following places, depending on the | |
f11fb629 | 204 | bootloader used: |
62de1c14 SI |
205 | |
206 | .Grub | |
207 | ||
208 | The kernel commandline needs to be placed in the variable | |
209 | `GRUB_CMDLINE_LINUX_DEFAULT` in the file `/etc/default/grub`. Running | |
210 | `update-grub` appends its content to all `linux` entries in | |
211 | `/boot/grub/grub.cfg`. | |
212 | ||
213 | .Systemd-boot | |
214 | ||
0aebb0d9 | 215 | The kernel commandline needs to be placed as one line in `/etc/kernel/cmdline`. |
ab2bc36e | 216 | To apply your changes, run `pve-efiboot-tool refresh`, which sets it as the |
0aebb0d9 | 217 | `option` line for all config files in `loader/entries/proxmox-*.conf`. |