我安装了 Ubuntu 18.04 并只创建了一个分区（根）。启动系统需要 2 分钟以上的时间。我读过类似的帖子，但不明白如何向您提供有关该问题的必要信息。
przem@przem-X510UNR:~$ systemd-analyze blame
22.383s plymouth-quit-wait.service
15.690s NetworkManager-wait-online.service
12.661s apt-daily.service
3.637s apt-daily-upgrade.service
2.884s dev-sdb5.device
2.493s snapd.service
2.429s systemd-logind.service
2.385s gpu-manager.service
794ms fwupd.service
605ms systemd-journal-flush.service
496ms dev-loop1.device
490ms snap-gnome\x2dsystem\x2dmonitor-127.mount
478ms dev-loop2.device
469ms snap-core-8592.mount
449ms snap-gnome\x2d3\x2d28\x2d1804-67.mount
448ms dev-loop0.device
400ms snap-gnome\x2dcalculator-406.mount
400ms dev-loop3.device
381ms snap-gtk\x2dcommon\x2dthemes-1440.mount
356ms snap-core-7270.mount
351ms dev-loop4.device
336ms snap-core18-1066.mount
314ms snap-gnome\x2d3\x2d28\x2d1804-116.mount
313ms dev-loop5.device
303ms snap-gnome\x2dcalculator-544.mount
301ms dev-loop6.device
301ms snap-gnome\x2dcharacters-296.mount
276ms dev-loop7.device
266ms dev-loop10.device
261ms dev-loop8.device
261ms snap-gnome\x2dlogs-81.mount
259ms snap-gtk\x2dcommon\x2dthemes-1313.mount
255ms systemd-udevd.service
254ms dev-loop9.device
227ms dev-loop12.device
226ms dev-loop11.device
211ms networkd-dispatcher.service
196ms udisks2.service
195ms dev-loop14.device
190ms dev-loop13.device
190ms systemd-timesyncd.service
189ms systemd-resolved.service
183ms NetworkManager.service
169ms snap-gnome\x2dsystem\x2dmonitor-100.mount
160ms snap-gnome\x2dlogs-61.mount
145ms dev-loop15.device
144ms ModemManager.service
139ms grub-common.service
130ms accounts-daemon.service
125ms systemd-udev-trigger.service
113ms snap-core18-1668.mount
105ms snap-gnome\x2dcharacters-399.mount
103ms thermald.service
94ms systemd-rfkill.service
79ms polkit.service
65ms apparmor.service
64ms systemd-fsck@dev-disk-by\x2duuid-44ED\x2d1F02.service
61ms keyboard-setup.service
58ms motd-news.service
54ms systemd-tmpfiles-clean.service
53ms systemd-journald.service
53ms upower.service
49ms plymouth-start.service
46ms systemd-tmpfiles-setup-dev.service
43ms apport.service
39ms [email protected]
36ms packagekit.service
32ms wpa_supplicant.service
32ms bolt.service
30ms networking.service
30ms systemd-sysctl.service
29ms snapd.seeded.service
26ms systemd-modules-load.service
24ms systemd-remount-fs.service
23ms avahi-daemon.service
22ms systemd-backlight@leds:asus::kbd_backlight.service
21ms rsyslog.service
20ms bluetooth.service
16ms snapd.socket
16ms binfmt-support.service
15ms ureadahead-stop.service
15ms alsa-restore.service
14ms gdm.service
13ms colord.service
12ms systemd-backlight@backlight:intel_backlight.service
11ms plymouth-read-write.service
11ms speech-dispatcher.service
10ms systemd-random-seed.service
10ms systemd-tmpfiles-setup.service
9ms kerneloops.service
8ms boot-efi.mount
7ms pppd-dns.service
7ms dev-mqueue.mount
6ms systemd-update-utmp-runlevel.service
6ms dns-clean.service
6ms dev-hugepages.mount
6ms proc-sys-fs-binfmt_misc.mount
4ms kmod-static-nodes.service
4ms console-setup.service
4ms ufw.service
4ms systemd-update-utmp.service
3ms sys-kernel-debug.mount
3ms systemd-user-sessions.service
3ms rtkit-daemon.service
2ms sys-kernel-config.mount
2ms setvtrgb.service
2ms sys-fs-fuse-connections.mount
编辑1：
现在启动 Ubuntu 需要 1:37。我禁用了 NetworkManager-wait-online.service 和 apt-daily.service
20.763s plymouth-quit-wait.service
1.767s dev-sdb5.device
728ms snapd.service
604ms systemd-journal-flush.service
545ms dev-loop1.device
504ms dev-loop2.device
503ms fwupd.service
499ms dev-loop3.device
490ms snap-core-8592.mount
450ms dev-loop4.device
441ms snap-gnome\x2dcalculator-406.mount
441ms mnt-6414FEB114FE8578.mount
430ms snap-core18-1668.mount
397ms snap-core-7270.mount
389ms dev-loop0.device
386ms snap-gnome\x2d3\x2d28\x2d1804-116.mount
382ms systemd-timesyncd.service
381ms systemd-resolved.service
371ms snap-core18-1066.mount
369ms snap-gnome\x2dcharacters-399.mount
369ms snap-gnome\x2dlogs-81.mount
368ms dev-loop5.device
360ms dev-loop7.device
Startup finished in 6.108s (firmware) + 3.270s (loader) + 2.803s (kernel) + 3min 508ms (userspace) = 3min 12.691s
graphical.target reached after 1min 51.236s in userspace
graphical.target @1min 51.236s
└─multi-user.target @1min 51.236s
└─snapd.seeded.service @1min 31.034s +19ms
└─snapd.service @1min 30.305s +728ms
└─basic.target @1min 30.265s
└─sockets.target @1min 30.265s
└─snapd.socket @1min 30.265s +568us
└─sysinit.target @1min 30.258s
└─systemd-timesyncd.service @2.079s +382ms
└─systemd-tmpfiles-setup.service @2.062s +13ms
└─local-fs.target @2.061s
└─run-user-1000-gvfs.mount @1min 34.326s
└─run-user-1000.mount @1min 30.627s
└─local-fs-pre.target @314ms
└─systemd-tmpfiles-setup-dev.service @262ms+51ms
└─kmod-static-nodes.service @257ms +4ms
└─systemd-journald.socket @250ms
└─system.slice @250ms
└─-.slice @248ms
编辑2：
我可以删除这些快照吗？删除它们会有什么后果？
/etc/systemd/system$ systemctl list-unit-files | grep snap
snap-core-7270.mount enabled
snap-core-8592.mount enabled
snap-core18-1066.mount enabled
snap-core18-1668.mount enabled
snap-gnome\x2d3\x2d28\x2d1804-116.mount enabled
snap-gnome\x2d3\x2d28\x2d1804-67.mount enabled
snap-gnome\x2dcalculator-406.mount enabled
snap-gnome\x2dcalculator-544.mount enabled
snap-gnome\x2dcharacters-296.mount enabled
snap-gnome\x2dcharacters-399.mount enabled
snap-gnome\x2dlogs-61.mount enabled
snap-gnome\x2dlogs-81.mount enabled
snap-gnome\x2dsystem\x2dmonitor-100.mount enabled
snap-gnome\x2dsystem\x2dmonitor-127.mount enabled
snap-gtk\x2dcommon\x2dthemes-1313.mount enabled
snap-gtk\x2dcommon\x2dthemes-1440.mount enabled
snapd.autoimport.service enabled
snapd.core-fixup.service enabled
snapd.failure.service static
snapd.seeded.service enabled
snapd.service enabled
snapd.snap-repair.service static
snapd.system-shutdown.service enabled
snapd.socket enabled
snapd.snap-repair.timer enabled