我尝试安装 etherpad，但没有成功，但之后我的 ubuntu 20.04 启动非常慢，启动花费了太多时间。如果我看到系统分析时间，$ systemd-analyze time它显示如下
Startup finished in 3.852s (kernel) + 1min 36.385s (userspace) = 1min 40.237s
graphical.target reached after 1min 36.375s in userspace```How can I fix this and make to boot fast as before. `systemd-analyze blame` results as 1min 34.672s plymouth-quit-wait.service
6.332s NetworkManager-wait-online.service
5.805s fwupd.service
5.035s bolt.service
1.326s jenkins.service
924ms snapd.service
856ms snap-snapd-12057.mount
850ms snap-udemy-21.mount
829ms snap-gnome\x2d3\x2d34\x2d1804-72.mount
774ms snap-pycharm\x2dcommunity-238.mount
701ms gdm.service
577ms snap-snap\x2dstore-518.mount
576ms snap-snapd-11841.mount
575ms dev-loop0.device
546ms snap-core-11167.mount
543ms docker.service
536ms snap-pycharm\x2dcommunity-240.mount
470ms dev-loop3.device
467ms snap-gtk\x2dcommon\x2dthemes-1514.mount
463ms dev-loop2.device
452ms dev-loop4.device
449ms snap-gnome\x2d3\x2d28\x2d1804-128.mount
398ms snap-core-11081.mount
391ms dev-loop1.device
388ms snap-openboard-14.mount
387ms dev-loop5.device
386ms dev-loop6.device
373ms dev-nvme0n1p5.device
322ms snapd.seeded.service
283ms systemd-backlight@backlight:intel_backlight.service
279ms dev-loop8.device
279ms snap-snap\x2dstore-542.mount
265ms snap-gtk\x2dcommon\x2dthemes-1515.mount
246ms mariadb.service
216ms systemd-resolved.service
205ms networkd-dispatcher.service
191ms dev-loop9.device
191ms dev-loop7.device
189ms apparmor.service
173ms systemd-timesyncd.service
162ms snap-core18-2066.mount
160ms snap-gnome\x2d3\x2d34\x2d1804-66.mount
159ms containerd.service
150ms systemd-logind.service
149ms etherpad.service
147ms ua-messaging.service
144ms accounts-daemon.service
144ms dev-loop14.device
142ms dev-loop12.device
135ms snap-core18-1997.mount
134ms udisks2.service
123ms dev-loop13.device
122ms [email protected]
114ms dev-loop11.device
114ms dev-loop10.device
110ms [email protected]
109ms snap-gnome\x2d3\x2d28\x2d1804-145.mount
108ms upower.service
105ms systemd-udev-trigger.service
95ms [email protected]
89ms systemd-journal-flush.service
89ms keyboard-setup.service
83ms systemd-journald.service
82ms polkit.service
80ms dev-loop15.device
79ms avahi-daemon.service
72ms NetworkManager.service
70ms ModemManager.service
68ms iio-sensor-proxy.service
66ms nginx.service
66ms switcheroo-control.service
59ms systemd-udevd.service
58ms apport.service
52ms thermald.service
51ms lm-sensors.service
49ms wpa_supplicant.service
48ms systemd-tmpfiles-setup.service
47ms gpu-manager.service
44ms open-fprintd.service
44ms grub-common.service
43ms colord.service
43ms systemd-fsck@dev-disk-by\x2duuid-0E0A\x2dC8A2.service
42ms smartmontools.service
42ms ssh.service
36ms e2scrub_reap.service
35ms snapd.apparmor.service
34ms secureboot-db.service
31ms teamviewerd.service
29ms dev-loop16.device
27ms systemd-modules-load.service
25ms [email protected]
24ms systemd-update-utmp.service
22ms alsa-restore.service
20ms rsyslog.service
20ms systemd-sysusers.service
20ms swapfile.swap
19ms systemd-random-seed.service
19ms [email protected]
18ms boot-efi.mount
18ms bluetooth.service
18ms systemd-sysctl.service
17ms plymouth-start.service
17ms systemd-rfkill.service
16ms systemd-remount-fs.service
16ms systemd-backlight@leds:tpacpi::kbd_backlight.service
14ms plymouth-read-write.service
13ms dev-hugepages.mount
13ms dev-mqueue.mount
12ms kmod-static-nodes.service
12ms sys-kernel-debug.mount
12ms ufw.service
12ms sys-kernel-tracing.mount
11ms systemd-tmpfiles-clean.service
11ms pppd-dns.service
11ms grub-initrd-fallback.service
10ms [email protected]
10ms [email protected]
9ms kerneloops.service
9ms systemd-tmpfiles-setup-dev.service
8ms systemd-user-sessions.service
8ms systemd-update-utmp-runlevel.service
8ms sys-fs-fuse-connections.mount
7ms sysstat.service
7ms setvtrgb.service
7ms sys-kernel-config.mount
5ms console-setup.service
4ms openvpn.service
4ms dev-loop17.device
1ms rtkit-daemon.service
961us docker.socket
523us snapd.socket```