我是 ubuntu 16.04 的新用户。输入正确的密码登录桌面屏幕后，在它出现之前，大约有 10 秒的延迟，屏幕只显示桌面的默认壁纸。如果我注销并再次登录，则没有问题。我找到了一个可能的解决方案https://ubuntuforums.org/showthread.php?t=1490249建议禁用软盘，但解决方案太旧了，而且我认为我的笔记本电脑没有软盘端口。
我有 Dell inspiron 3542、4 GB RAM、Intel I5 @ 1.7Ghz x4 并使用 X.org X server-nouveau 驱动程序（更改为 Nvidia 没有帮助！）
如果需要任何其他详细信息，请评论。
编辑1：
$systemd-analyze blame
Bootup is not yet finished. Please try again later
编辑2：
$systemd-analyze blame
12.927s dev-sda1.device
7.691s systemd-udevd.service
5.165s snapd.service
3.362s fwupd.service
2.742s grub-common.service
2.468s systemd-tmpfiles-setup-dev.service
2.379s preload.service
2.333s apport.service
2.305s ondemand.service
2.107s irqbalance.service
2.028s speech-dispatcher.service
1.887s lightdm.service
1.752s plymouth-quit-wait.service
1.650s keyboard-setup.service
1.320s NetworkManager.service
1.187s gpu-manager.service
1.172s systemd-journald.service
1.116s systemd-modules-load.service
1.111s accounts-daemon.service
1.075s dev-hugepages.mount
1.073s sys-kernel-debug.mount
987ms dev-mqueue.mount
616ms apparmor.service
485ms kmod-static-nodes.service
442ms setvtrgb.service
442ms plymouth-start.service
441ms rsyslog.service
424ms ufw.service
335ms console-setup.service
314ms systemd-logind.service
303ms upower.service
301ms alsa-restore.service
295ms pppd-dns.service
294ms iio-sensor-proxy.service
291ms systemd-update-utmp.service
288ms systemd-user-sessions.service
282ms systemd-sysctl.service
281ms thermald.service
279ms avahi-daemon.service
268ms polkitd.service
172ms udisks2.service
156ms networking.service
145ms wpa_supplicant.service
108ms systemd-tmpfiles-setup.service
107ms systemd-rfkill.service
100ms systemd-udev-trigger.service
55ms dev-loop0.device
49ms dev-disk-by\x2duuid-c07aa9cb\x2dd0b5\x2d484f\x2dae1b\x2df78482d
47ms dev-loop1.device
33ms plymouth-read-write.service
32ms systemd-journal-flush.service
24ms [email protected]
24ms snap-chromium-353.mount
22ms snapd.seeded.service
18ms colord.service
17ms snap-core-4830.mount
17ms systemd-timesyncd.service
16ms dns-clean.service
14ms systemd-remount-fs.service
13ms bluetooth.service
6ms systemd-random-seed.service
6ms resolvconf.service
5ms rtkit-daemon.service
4ms ureadahead-stop.service
3ms systemd-update-utmp-runlevel.service
3ms sys-kernel-config.mount
2ms sys-fs-fuse-connections.mount
2ms systemd-backlight@backlight:intel_backlight.service
1ms systemd-backlight@leds:dell::kbd_backlight.service
1ms rc-local.service
475us snapd.socket