我使用的是 Ubuntu 18.04，内核是 4.15.0.29-generic。启动过程需要很长时间，而且我注意到启动时字体样式会发生变化。我已经在谷歌上尝试了很多方法，但都没有效果，所以我恢复到安装后的快照（这个），因为其他方法都无法解决我的问题。（我使用的是 Timeshift）
PS 我尝试自己做一些调试和研究，但 3 个小时后我什么也没找到。
PSS 这在内核 4.18 上仍然存在。（为此进行了尝试）
启动日志(/var/log/boot.log):
[FAILED] Failed to start Set console font and keymap.
See 'systemctl status console-setup.service' for details.
[ OK ] Started AppArmor initialization.
Starting Raise network interfaces...
[ OK ] Started Raise network interfaces.
[ OK ] Started Network Name Resolution.
[ OK ] Reached target Host and Network Name Lookups.
[ OK ] Started Network Time Synchronization.
[ OK ] Reached target System Time Synchronized.
[ OK ] Reached target System Initialization.
[ OK ] Started Message of the Day.
Starting Socket activation for snappy daemon.
[ OK ] Started Daily Cleanup of Temporary Directories.
[ OK ] Started CUPS Scheduler.
[ OK ] Listening on ACPID Listen Socket.
[ OK ] Started Daily apt download activities.
[ OK ] Started Daily apt upgrade and clean activities.
[ OK ] Started Discard unused blocks once a week.
[ OK ] Started Trigger anacron every hour.
[ OK ] Reached target Timers.
[ OK ] Listening on D-Bus System Message Bus Socket.
[ OK ] Listening on UUID daemon activation socket.
[ OK ] Listening on CUPS Scheduler.
[ OK ] Listening on Avahi mDNS/DNS-SD Stack Activation Socket.
[ OK ] Started ACPI Events Check.
[ OK ] Reached target Paths.
[ OK ] Listening on Socket activation for snappy daemon.
[ OK ] Reached target Sockets.
[ OK ] Reached target Basic System.
[ OK ] Started D-Bus System Message Bus.
[ OK ] Started Set the CPU Frequency Scaling governor.
Starting Accounts Service...
[ OK ] Started Run anacron jobs.
Starting Dispatcher daemon for systemd-networkd...
[ OK ] Started Regular background program processing daemon.
Starting NVIDIA Persistence Daemon...
Starting Detect the available GPUs and deal with any system changes...
Starting Network Manager...
Starting LSB: Speech Dispatcher...
[ OK ] Reached target Login Prompts.
Starting Snappy daemon...
Starting Modem Manager...
Starting Thermal Daemon Service...
[ OK ] Started ACPI event daemon.
Starting Restore /etc/resolv.conf if the system crashed before the ppp link was shut down...
[ OK ] Started irqbalance daemon.
[ OK ] Started CUPS Scheduler.
[ OK ] Reached target Printer.
Starting Login Service...
Starting LSB: automatic crash report generation...
Starting Avahi mDNS/DNS-SD Stack...
Starting Disk Manager...
Starting LSB: Record successful boot for GRUB...
Starting System Logging Service...
Starting WPA supplicant...
Starting Save/Restore Sound Card State...
[ OK ] Started NVIDIA Persistence Daemon.
[ OK ] Started Restore /etc/resolv.conf if the system crashed before the ppp link was shut down.
[ OK ] Started LSB: Speech Dispatcher.
[ OK ] Started LSB: automatic crash report generation.
[ OK ] Started Save/Restore Sound Card State.
[ OK ] Started LSB: Record successful boot for GRUB.
[ OK ] Started Avahi mDNS/DNS-SD Stack.
[ OK ] Started Make remote CUPS printers available locally.
[ OK ] Started WPA supplicant.
Starting Authorization Manager...
[ OK ] Started System Logging Service.
[ OK ] Started Detect the available GPUs and deal with any system changes.
[ OK ] Started Authorization Manager.
[ OK ] Started Accounts Service.
[ OK ] Started Thermal Daemon Service.
[ OK ] Started Modem Manager.
Starting Hostname Service...
[ OK ] Started Hostname Service.
[ OK ] Started Dispatcher daemon for systemd-networkd.
[ OK ] Started Disk Manager.
[ OK ] Started Network Manager.
Starting Network Manager Wait Online...
[ OK ] Reached target Network.
Starting Permit User Sessions...
Starting Network Manager Script Dispatcher Service...
[ OK ] Started Permit User Sessions.
Starting Hold until boot process finishes up...
Starting GNOME Display Manager...
[ OK ] Started Network Manager Script Dispatcher Service.
[ OK ] Started GNOME Display Manager.
[** ] (3 of 6) A start job is running for Network Time Synchronization (31s /[ OK ] Mounted Mount unit for gnome-calculator, revision 180.
[ OK ] Mounted Mount unit for gnome-3-26-1604, revision 70.
[ OK ] Mounted Mount unit for gnome-logs, revision 37.
[ OK ] Started Set console font and keymap.
[ OK ] Started Network Name Resolution.
[ OK ] Reached target Host and Network Name Lookups.
[ OK ] Started Network Time Synchronization.
[ OK ] Reached target System Time Synchronized.
[ OK ] Reached target System Initialization.
[ OK ] Listening on ACPID Listen Socket.
Starting Socket activation for snappy daemon.
[ OK ] Started Trigger anacron every hour.
[ OK ] Started CUPS Scheduler.
[ OK ] Started Daily Cleanup of Temporary Directories.
[ OK ] Listening on D-Bus System Message Bus Socket.
[ OK ] Listening on CUPS Scheduler.
[ OK ] Listening on Avahi mDNS/DNS-SD Stack Activation Socket.
[ OK ] Started Daily apt download activities.
[ OK ] Started Daily apt upgrade and clean activities.
[ OK ] Listening on UUID daemon activation socket.
[ OK ] Started Discard unused blocks once a week.
[ OK ] Started Message of the Day.
[ OK ] Started ACPI Events Check.
[ OK ] Reached target Paths.
[ OK ] Reached target Timers.
[ OK ] Listening on Socket activation for snappy daemon.
[ OK ] Reached target Sockets.
[ OK ] Reached target Basic System.
Starting Login Service...
Starting Thermal Daemon Service...
Starting Disk Manager...
Starting Dispatcher daemon for systemd-networkd...
[ OK ] Started Run anacron jobs.
[ OK ] Started CUPS Scheduler.
[ OK ] Reached target Printer.
[ OK ] Started D-Bus System Message Bus.
Starting WPA supplicant...
Starting System Logging Service...
Starting LSB: Speech Dispatcher...
Starting Modem Manager...
Starting Restore /etc/resolv.conf if the system crashed before the ppp link was shut down...
[ OK ] Started Set the CPU Frequency Scaling governor.
[ OK ] Started irqbalance daemon.
Starting Save/Restore Sound Card State...
Starting Detect the available GPUs and deal with any system changes...
Starting Avahi mDNS/DNS-SD Stack...
Starting Snappy daemon...
Starting LSB: automatic crash report generation...
[ OK ] Started Regular background program processing daemon.
Starting LSB: Record successful boot for GRUB...
[ OK ] Reached target Login Prompts.
[ OK ] Started ACPI event daemon.
Starting Accounts Service...
Starting Network Manager...
[ OK ] Started Restore /etc/resolv.conf if the system crashed before the ppp link was shut down.
[ OK ] Started Save/Restore Sound Card State.
[ OK ] Started LSB: Speech Dispatcher.
[ OK ] Started Thermal Daemon Service.
[ OK ] Started WPA supplicant.
[ OK ] Started Avahi mDNS/DNS-SD Stack.
[ OK ] Started Make remote CUPS printers available locally.
[ OK ] Started System Logging Service.
Starting Authorization Manager...
[ OK ] Started LSB: automatic crash report generation.
[ OK ] Started LSB: Record successful boot for GRUB.
[ OK ] Started Detect the available GPUs and deal with any system changes.
[ OK ] Started Authorization Manager.
[ OK ] Started Accounts Service.
[ OK ] Started Modem Manager.
[ OK ] Started Dispatcher daemon for systemd-networkd.
Starting Hostname Service...
[ OK ] Started Disk Manager.
[ OK ] Started Login Service.
[ OK ] Started Snappy daemon.
Starting Wait until snapd is fully seeded...
[ OK ] Started Wait until snapd is fully seeded.
[ OK ] Started Hostname Service.
[ OK ] Started Network Manager.
[ OK ] Reached target Network.
Starting Permit User Sessions...
[ OK ] Started Unattended Upgrades Shutdown.
Starting Network Manager Wait Online...
[ OK ] Started Permit User Sessions.
Starting GNOME Display Manager...
Starting Hold until boot process finishes up...
Starting Network Manager Script Dispatcher Service...
[ OK ] Started Network Manager Script Dispatcher Service.
[ OK ] Started GNOME Display Manager.
更新：
systemctl status console-setup.service 显示：
● console-setup.service - Set console font and keymap
Loaded: loaded (/lib/systemd/system/console-setup.service; enabled; vendor pr
Active: active (exited) since Sat 2019-02-16 10:58:11 EET; 1min 22s ago
Process: 697 ExecStart=/lib/console-setup/console-setup.sh (code=exited, statu
Main PID: 697 (code=exited, status=0/SUCCESS)
feb 16 10:58:11 Motan systemd[1]: Starting Set console font and keymap...
feb 16 10:58:11 Motan systemd[1]: Started Set console font and keymap.
free -h 显示：
total used free shared buff/cache available
Mem: 15G 1,5G 11G 61M 2,0G 13G
Swap: 1,7G 0B 1,7G
swapon 显示：
NAME TYPE SIZE USED PRIO
/swapfile file 1,7G 0B -2
sudo blkid 显示：
/dev/sdb1: UUID="bbfdf8d9-be18-4d3d-b6fa-d0caec4db4ed" TYPE="ext4" PARTUUID="51599328-01"
/dev/loop0: TYPE="squashfs"
/dev/loop1: TYPE="squashfs"
/dev/loop2: TYPE="squashfs"
/dev/loop3: TYPE="squashfs"
/dev/loop4: TYPE="squashfs"
/dev/loop5: TYPE="squashfs"
/dev/loop6: TYPE="squashfs"
/dev/sda1: LABEL="Recovery" UUID="3A9496D094968DCF" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="693b5e90-b593-407e-a5f7-b03d3cdd5b81"
/dev/sda2: UUID="3A96-E631" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="5412b97f-6607-4c6d-8239-6343b5ca7be9"
/dev/sda3: PARTLABEL="Microsoft reserved partition" PARTUUID="3f5148bb-b8d2-4578-bb7b-d90ef29c5851"
/dev/sda4: UUID="AC4AA1C54AA18D20" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="c3405128-e084-4cd6-87f8-0337205d9568"
/dev/sdb5: UUID="bb8f025a-c48e-4ab0-a0e7-ae935adeade1" TYPE="ext4" PARTUUID="51599328-05"
/dev/sdb6: UUID="fdef4d1c-39e4-4a3c-ac71-ff0b6791cae1" TYPE="ext4" PARTUUID="51599328-06"
/dev/sdc1: LABEL="Data" UUID="6846CE9F46CE6D7E" TYPE="ntfs" PARTUUID="9726fa2c-01"
cat /etc/fstab 显示：
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sdb1 during installation
UUID=bbfdf8d9-be18-4d3d-b6fa-d0caec4db4ed / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda2 during installation
UUID=3A96-E631 /boot/efi vfat umask=0077 0 1
# /home was on /dev/sdb6 during installation
UUID=fdef4d1c-39e4-4a3c-ac71-ff0b6791cae1 /home ext4 defaults 0 2
# /var was on /dev/sdb5 during installation
UUID=bb8f025a-c48e-4ab0-a0e7-ae935adeade1 /var ext4 defaults 0 2
/swapfile none swap sw 0 0
答案1
虽然我之前已经更新过系统，但系统更新后问题已经消失。无需进一步研究。