我有一台服务器在两个 SSD 上的 RAID-1 mdraid 上运行，并且已加密。启动机器后，/boot（也是 EFI 分区）不会自动挂载，而它应该是自动挂载的。正常开机后的状态：
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 931,5G 0 disk
├─sda1 8:1 0 500M 0 part
│ └─md127 9:127 0 499,9M 0 raid1
└─sda2 8:2 0 930G 0 part
└─md126 9:126 0 929,9G 0 raid1
└─root 253:0 0 929,9G 0 crypt /
sdb 8:16 0 931,5G 0 disk
├─sdb1 8:17 0 500M 0 part
│ └─md127 9:127 0 499,9M 0 raid1
└─sdb2 8:18 0 930G 0 part
└─md126 9:126 0 929,9G 0 raid1
└─root 253:0 0 929,9G 0 crypt /
$ cat /proc/cmdline
initrd=\intel-ucode.img initrd=\initramfs-linux.img root=UUID=2b9dc231-ed74-442c-841d-8254d3d7e91a rw rd.luks.options=bf4b8b61-5907-408c-8fcb-65f77e34cc86=keyfile-timeout=10s rd.luks.key=bf4b8b61-5907-408c-8fcb-65f77e34cc86=/keyfile:UUID=B332-1C72 rd.luks.name=bf4b8b61-5907-408c-8fcb-65f77e34cc86=root init=/usr/lib/systemd/systemd quiet
$ sudo mdadm --detail /dev/md126
/dev/md126:
Version : 1.2
Creation Time : Fri Nov 13 12:32:44 2020
Raid Level : raid1
Array Size : 975043584 (929.87 GiB 998.44 GB)
Used Dev Size : 975043584 (929.87 GiB 998.44 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Fri Jul 16 13:50:39 2021
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Consistency Policy : bitmap
Name : archiso:cryptroot
UUID : e4353e5f:188eaaa7:afbb8df6:a1a914bb
Events : 5329
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
2 8 18 1 active sync /dev/sdb2
$ sudo mdadm --detail /dev/md127
/dev/md127:
Version : 1.0
Creation Time : Fri Nov 13 15:41:39 2020
Raid Level : raid1
Array Size : 511936 (499.94 MiB 524.22 MB)
Used Dev Size : 511936 (499.94 MiB 524.22 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Jul 16 13:46:13 2021
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Consistency Policy : resync
Name : archiso:efi
UUID : 457d2b2d:e0f98963:65fb2d50:43d742ad
Events : 150
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
2 8 17 1 active sync /dev/sdb1
$ mount
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
devtmpfs on /dev type devtmpfs (rw,nosuid,size=4007800k,nr_inodes=1001950,mode=755,inode64)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,inode64)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,size=1613448k,nr_inodes=819200,mode=755,inode64)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime)
none on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
/dev/mapper/root on / type ext4 (rw,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=31,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=13578)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,nr_inodes=409600,inode64)
tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,nosuid,nodev,noexec,relatime)
none on /run/credentials/systemd-sysusers.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=806720k,nr_inodes=201680,mode=700,uid=1000,gid=1001,inode64)
$ cat /etc/fstab
# /dev/mapper/root LABEL=root
UUID=2b9dc231-ed74-442c-841d-8254d3d7e91a / ext4 rw,relatime 0 1
# tracefs
tracefs /sys/kernel/tracing tracefs rw,nosuid,nodev,noexec 0 0
# /dev/md127 LABEL=EFI
UUID=B332-1C72 /boot vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro 0 2
$ cat /etc/mkinitcpio.conf
# vim:set ft=sh
# MODULES
# The following modules are loaded before any boot hooks are
# run. Advanced users may wish to specify all system modules
# in this array. For instance:
# MODULES="piix ide_disk reiserfs"
MODULES=(vfat)
# BINARIES
# This setting includes any additional binaries a given user may
# wish into the CPIO image. This is run last, so it may be used to
# override the actual binaries included by a given hook
# BINARIES are dependency parsed, so you may safely ignore libraries
BINARIES=()
# FILES
# This setting is similar to BINARIES above, however, files are added
# as-is and are not parsed in any way. This is useful for config files.
FILES=()
# HOOKS
# This is the most important setting in this file. The HOOKS control the
# modules and scripts added to the image, and what happens at boot time.
# Order is important, and it is recommended that you do not change the
# order in which HOOKS are added. Run 'mkinitcpio -H <hook name>' for
# help on a given hook.
# 'base' is _required_ unless you know precisely what you are doing.
# 'udev' is _required_ in order to automatically load modules
# 'filesystems' is _required_ unless you specify your fs modules in MODULES
# Examples:
## This setup specifies all modules in the MODULES setting above.
## No raid, lvm2, or encrypted root is needed.
# HOOKS="base"
#
## This setup will autodetect all modules for your system and should
## work as a sane default
# HOOKS="base udev autodetect block filesystems"
#
## This setup will generate a 'full' image which supports most systems.
## No autodetection is done.
# HOOKS="base udev block filesystems"
#
## This setup assembles a pata mdadm array with an encrypted root FS.
## Note: See 'mkinitcpio -H mdadm' for more information on raid devices.
# HOOKS="base udev block mdadm encrypt filesystems"
#
## This setup loads an lvm2 volume group on a usb device.
# HOOKS="base udev block lvm2 filesystems"
#
## NOTE: If you have /usr on a separate partition, you MUST include the
# usr, fsck and shutdown hooks.
HOOKS=(base systemd autodetect keyboard sd-vconsole modconf block mdadm_udev sd-encrypt filesystems fsck)
# COMPRESSION
# Use this to compress the initramfs image. By default, gzip compression
# is used. Use 'cat' to create an uncompressed image.
#COMPRESSION="gzip"
#COMPRESSION="bzip2"
#COMPRESSION="lzma"
#COMPRESSION="xz"
#COMPRESSION="lzop"
#COMPRESSION="lz4"
COMPRESSION="cat"
# COMPRESSION_OPTIONS
# Additional options for the compressor
#COMPRESSION_OPTIONS=""
$ sudo find /run/systemd/ -name *.mount
/run/systemd/generator/boot.mount
/run/systemd/generator/sys-kernel-tracing.mount
/run/systemd/generator/local-fs.target.requires/boot.mount
/run/systemd/generator/local-fs.target.requires/sys-kernel-tracing.mount
/run/systemd/generator/local-fs.target.requires/-.mount
/run/systemd/generator/-.mount
/run/systemd/units/invocation:sys-fs-fuse-connections.mount
/run/systemd/units/invocation:sys-kernel-config.mount
/run/systemd/units/invocation:tmp.mount
/run/systemd/units/invocation:sys-kernel-tracing.mount
/run/systemd/units/invocation:sys-kernel-debug.mount
/run/systemd/units/invocation:dev-mqueue.mount
/run/systemd/units/invocation:dev-hugepages.mount
/run/systemd/units/invocation:sysroot.mount
$ sudo cat /run/systemd/generator/boot.mount
# Automatically generated by systemd-fstab-generator
[Unit]
Documentation=man:fstab(5) man:systemd-fstab-generator(8)
SourcePath=/etc/fstab
Before=local-fs.target
After=blockdev@dev-disk-by\x2duuid-B332\x2d1C72.target
[Mount]
Where=/boot
What=/dev/disk/by-uuid/B332-1C72
Type=vfat
Options=rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro
$ cat /run/systemd/generator/local-fs.target.requires/boot.mount
# Automatically generated by systemd-fstab-generator
[Unit]
Documentation=man:fstab(5) man:systemd-fstab-generator(8)
SourcePath=/etc/fstab
Before=local-fs.target
After=blockdev@dev-disk-by\x2duuid-B332\x2d1C72.target
[Mount]
Where=/boot
What=/dev/disk/by-uuid/B332-1C72
Type=vfat
Options=rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro
当我sudo mount -a重新启动后运行时，/boot 分区已挂载且没有错误。为什么/boot没有自动挂载？为什么只能手动操作？
更新
$ systemctl status boot.mount
○ boot.mount - /boot
Loaded: loaded (/etc/fstab; generated)
Active: inactive (dead) since Thu 2021-08-05 10:07:28 CEST; 48s ago
Where: /boot
What: /dev/disk/by-uuid/B332-1C72
Docs: man:fstab(5)
man:systemd-fstab-generator(8)
CPU: 5ms
Aug 05 10:07:28 offsrv systemd[1]: Unmounting /boot...
Aug 05 10:07:28 offsrv systemd[1]: boot.mount: Deactivated successfully.
Aug 05 10:07:28 offsrv systemd[1]: Unmounted /boot.
$ journalctl -au boot.mount
-- Journal begins at Fri 2021-07-23 02:09:41 CEST, ends at Thu 2021-08-05 10:08:02 CEST. --
Jul 26 19:53:05 offsrv systemd[1]: Unmounting /boot...
Jul 26 19:53:05 offsrv systemd[1]: boot.mount: Deactivated successfully.
Jul 26 19:53:05 offsrv systemd[1]: Unmounted /boot.
-- Boot c3526248def14c31869cf62cc450e680 --
Jul 26 19:53:26 offsrv systemd[1]: Unmounting /boot...
Jul 26 19:53:26 offsrv systemd[1]: boot.mount: Deactivated successfully.
Jul 26 19:53:26 offsrv systemd[1]: Unmounted /boot.
-- Boot 6b6baf91260148e5a3e70e94a48c26a9 --
Aug 03 14:06:56 offsrv systemd[1]: Unmounting /boot...
Aug 03 14:06:56 offsrv systemd[1]: boot.mount: Deactivated successfully.
Aug 03 14:06:56 offsrv systemd[1]: Unmounted /boot.
-- Boot 5bf6c69ef8e0452388e425f7fbd0d75e --
Aug 03 14:07:15 offsrv systemd[1]: Unmounting /boot...
Aug 03 14:07:15 offsrv systemd[1]: boot.mount: Deactivated successfully.
Aug 03 14:07:15 offsrv systemd[1]: Unmounted /boot.
Aug 05 10:07:06 offsrv systemd[1]: Unmounting /boot...
Aug 05 10:07:06 offsrv systemd[1]: boot.mount: Deactivated successfully.
Aug 05 10:07:06 offsrv systemd[1]: Unmounted /boot.
-- Boot 3845a0a027984e5995d42ac52c87813f --
Aug 05 10:07:28 offsrv systemd[1]: Unmounting /boot...
Aug 05 10:07:28 offsrv systemd[1]: boot.mount: Deactivated successfully.
Aug 05 10:07:28 offsrv systemd[1]: Unmounted /boot.
答案1
经过更多修补后，结果发现文件系统存在一个小问题，我使用以下方法检测并修复了该问题dosfstools：
$ sudo dosfsck /dev/md126
fsck.fat 4.2 (2021-01-31)
There are differences between boot sector and its backup.
This is mostly harmless. Differences: (offset:original/backup)
65:01/00
1) Copy original to backup
2) Copy backup to original
3) No action
[123?q]? 1
Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
1) Remove dirty bit
2) No action
[12?q]? 1
*** Filesystem was changed ***
The changes have not yet been written, you can still choose to leave the
filesystem unmodified:
1) Write changes
2) Leave filesystem unchanged
[12?q]? 1
/dev/md126: 17 files, 11536/127730 clusters
之后，/boot将自动安装（通过多次重新启动进行测试）。遗憾的是，systemd 相应的挂载单元没有记录/报告这个问题，所以我不知道发生了什么。