[编辑] 我刚刚意识到 Ubuntu 没有安装在 SSD 上 - 我只是假设它安装了。
我按照此说明在 Dell Inspirion 的 HDD 上安装了 Ubuntu 19.10 https://askubuntu.com/a/1127541/1022455
SSD 上的 Windows 启动时间约为 16 秒，Ubuntu 启动时间约为 55 秒。
$ systemd-analyze time
Startup finished in 3.204s (kernel) + 1min 18.943s (userspace) = 1min 22.147s
graphical.target reached after 1min 18.837s in userspace
$ systemd-analyze blame
52.979s plymouth-quit-wait.service
14.469s dev-sda3.device
10.106s NetworkManager-wait-online.service
9.651s networkd-dispatcher.service
9.650s systemd-journal-flush.service
9.455s snapd.service
8.486s ModemManager.service
7.680s udisks2.service
7.272s accounts-daemon.service
6.186s dev-loop0.device
5.571s grub-common.service
5.399s secureboot-db.service
5.328s apport.service
4.636s NetworkManager.service
4.561s switcheroo-control.service
4.559s rsyslog.service
4.555s grub-initrd-fallback.service
4.554s thermald.service
4.551s bluetooth.service
4.505s plymouth-read-write.service
4.496s dev-loop4.device
4.342s avahi-daemon.service
3.942s systemd-logind.service
3.940s gpu-manager.service
3.935s pppd-dns.service
3.640s apparmor.service
3.623s wpa_supplicant.service
3.601s dev-loop2.device
3.367s dev-loop5.device
3.101s e2scrub_reap.service
3.055s dev-loop3.device
3.031s dev-loop1.device
3.002s dev-loop6.device
2.816s systemd-resolved.service
2.552s systemd-udevd.service
2.152s plymouth-start.service
1.692s gdm.service
1.624s packagekit.service
1.515s polkit.service
1.011s systemd-backlight@leds:dell::kbd_backlight.service
744ms systemd-modules-load.service
674ms systemd-rfkill.service
642ms systemd-backlight@backlight:intel_backlight.service
639ms systemd-timesyncd.service
619ms upower.service
615ms systemd-sysusers.service
586ms systemd-sysctl.service
540ms keyboard-setup.service
498ms snap-core-7917.mount
441ms systemd-journald.service
439ms systemd-fsck@dev-disk-by\x2duuid-3637\x2dAEF4.service
434ms systemd-udev-trigger.service
349ms snap-core18-1223.mount
332ms snap-gnome\x2d3\x2d28\x2d1804-71.mount
319ms snapd.seeded.service
307ms systemd-random-seed.service
303ms snap-gtk\x2dcommon\x2dthemes-1353.mount
300ms snap-gnome\x2dlogs-81.mount
278ms snap-gnome\x2dcharacters-317.mount
264ms systemd-tmpfiles-setup-dev.service
260ms ufw.service
232ms snap-gnome\x2dcalculator-501.mount
232ms systemd-tmpfiles-setup.service
229ms systemd-user-sessions.service
211ms systemd-remount-fs.service
203ms colord.service
180ms [email protected]
159ms dev-mqueue.mount
122ms systemd-update-utmp.service
118ms kerneloops.service
104ms openvpn.service
100ms setvtrgb.service
87ms rtkit-daemon.service
81ms sys-kernel-debug.mount
81ms kmod-static-nodes.service
79ms dev-hugepages.mount
63ms boot-efi.mount
23ms snapd.socket
21ms systemd-update-utmp-runlevel.service
17ms console-setup.service
9ms [email protected]
2ms sys-fs-fuse-connections.mount
1ms sys-kernel-config.mount
$ systemd-analyze critical-chain
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.
graphical.target @51.809s
└─multi-user.target @51.809s
└─kerneloops.service @38.653s +213ms
└─network-online.target @38.622s
└─NetworkManager-wait-online.service @27.210s +11.411s
└─NetworkManager.service @21.074s +6.118s
└─dbus.service @21.071s
└─basic.target @20.653s
└─sockets.target @20.653s
└─snapd.socket @20.652s +755us
└─sysinit.target @20.605s
└─cryptsetup.target @20.590s
└─systemd-ask-password-wall.path @2.550s
└─-.mount @2.548s
└─system.slice @2.548s
└─-.slice @2.548s
我浏览了建议的链接，以下是结果
谢谢你的帮助。我认为第一个链接不是同一个问题，我的启动过程中没有apt-daily。
关闭交换（我有 16GB 的 RAM，默认交换是 1GB）
$ systemd-analyze time
Startup finished in 3.352s (kernel) + 51.883s (userspace) = 55.236s
graphical.target reached after 51.809s in userspace
sudo apt autoremove --purge snapd
$ systemd-analyze time
Startup finished in 3.325s (kernel) + 45.791s (userspace) = 49.117s
graphical.target reached after 45.708s in userspace
编辑日志：https://askubuntu.com/a/1094543/1022455
$ systemd-analyze time
Startup finished in 3.536s (kernel) + 41.438s (userspace) = 44.974s
graphical.target reached after 41.373s in userspace
不知道还有什么值得做的吗？Ubuntu 的预期启动时间是多少？它仍然比 ubuntu 慢
[编辑] 更新critical chain
graphical.target @28.709s
└─multi-user.target @28.709s
└─kerneloops.service @28.554s +153ms
└─network-online.target @28.552s
└─NetworkManager-wait-online.service @19.311s +9.240s
└─NetworkManager.service @14.001s +5.306s
└─dbus.service @13.994s
└─basic.target @13.911s
└─paths.target @13.911s
└─acpid.path @13.911s
└─sysinit.target @13.578s
└─systemd-timesyncd.service @12.952s +626ms
└─systemd-tmpfiles-setup.service @11.804s +1.108s
└─systemd-journal-flush.service @3.142s +8.661s
└─systemd-journald.service @2.808s +332ms
└─syslog.socket @2.806s
└─system.slice @2.572s
└─-.slice @2.572s
答案1
我已经在帖子中回答了这个问题系统启动缓慢 其中我已经列出了哪些服务可以安全禁用以及如何禁用它们。