我全新安装了 Ubuntu 16.04 和 Windows 10，并采用 UEFI 模式。安装时启动时间正常。安装后apt 升级，启动时间增加了。
输出systemd-analyze 责备：
24.771s dev-sda6.device
12.795s systemd-udevd.service
7.089s gpu-manager.service
7.023s NetworkManager-wait-online.service
6.925s systemd-tmpfiles-setup-dev.service
4.919s systemd-sysctl.service
3.829s snapd.service
3.216s NetworkManager.service
3.065s accounts-daemon.service
2.955s ModemManager.service
2.498s thermald.service
2.008s udisks2.service
1.954s systemd-modules-load.service
1.863s keyboard-setup.service
1.512s tlp.service
1.325s grub-common.service
1.030s systemd-journald.service
909ms dev-hugepages.mount
907ms dev-mqueue.mount
906ms sys-kernel-debug.mount
716ms systemd-fsck@dev-disk-by\x2duuid-445B\x2d8843.service
700ms apparmor.service
657ms ufw.service
600ms console-setup.service
570ms upower.service
546ms systemd-tmpfiles-setup.service
461ms rsyslog.service
439ms kmod-static-nodes.service
415ms irqbalance.service
414ms wpa_supplicant.service
349ms bluetooth.service
316ms polkitd.service
278ms colord.service
215ms avahi-daemon.service
201ms apport.service
166ms snapd.socket
159ms lightdm.service
141ms plymouth-read-write.service
135ms systemd-update-utmp.service
132ms systemd-remount-fs.service
111ms [email protected]
91ms setvtrgb.service
80ms boot-efi.mount
80ms systemd-hostnamed.service
78ms systemd-udev-trigger.service
63ms networking.service
62ms systemd-timesyncd.service
47ms systemd-journal-flush.service
36ms systemd-logind.service
33ms ondemand.service
28ms systemd-random-seed.service
27ms speech-dispatcher.service
15ms systemd-user-sessions.service
14ms plymouth-start.service
11ms alsa-restore.service
10ms snapd.autoimport.service
10ms pppd-dns.service
6ms dns-clean.service
4ms rtkit-daemon.service
4ms ureadahead-stop.service
4ms systemd-update-utmp-runlevel.service
4ms resolvconf.service
3ms sys-fs-fuse-connections.mount
2ms rc-local.service
1ms systemd-backlight@backlight:intel_backlight.service
1ms plymouth-quit-wait.service
1ms nvidia-persistenced.service
systemd-analyze 时间的输出：
Startup finished in 3.498s (firmware) + 3.332s (loader) + 6.081s (kernel)
+ 3min 3.648s (userspace) = 3min 16.561s
系统信息：
Laptop
Memory: 8 GB
Processor: Intel® Core™ i5-8250U CPU @ 1.60GHz × 8
Graphic: Intel® Kabylake GT1.5 and NVIDIA MX150(disabled)
/etc/fstab 的内容
# /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/sda6 during installation
# /boot/efi was on /dev/sda1 during installation
UUID=445B-8843 /boot/efi vfat umask=0077 0 1
# swap was on /dev/sda7 during installation
# UUID=96ded05b-556c-4459-9bcc-184ac5c21c2f none swap sw 0 0
/dev/mapper/cryptswap1 none swap sw 0 0
UUID=8534b107-3576-4f00-9150-2081f1e2f430 / ext4 rw,relatime,data=ordered 0 1
答案1
呵呵，非常奇怪。
启动用时 3.498 秒（固件）+ 3.332 秒（加载器）+ 6.081 秒（内核）+ 3 分 3.648 秒（用户空间）= 3 分 16.561 秒
用户空间中什么花了 3 分钟？
还有这两个：
24.771s dev-sda6.device
12.795s systemd-udevd.service
我觉得启动磁盘驱动器时出了问题。磁盘出问题了吗？你在做什么不寻常的事吗etc/fstab？磁盘加密？
我首先要研究一下你的驱动器是如何安装的。
此外，微软花费了额外的时间和精力来搞乱多操作系统的安装。出于这个原因，我在笔记本电脑上只使用 Linux - 我有一台装有 Windows 的廉价台式机，用于兼容性测试。
UEFI 几乎就是{插入咆哮}。微软喜欢这个，因为它有很多好处。在 BIOS 中关闭 UEFI 可能会有帮助（但 Windows 可能会抱怨）。