我在 Ubuntu 20.04 上遇到了极慢的启动速度。我有一台联想 Thinkpad X201。对于我在另一个分区上安装的另一个 Ubuntu 18.04，启动时间不会那么长。
在终端中运行 dmesg 并读取输出显示以下可能与启动延迟有关的行：
[ 39.616283] audit: type=1400 audit(1626546618.403:82): apparmor="DENIED" operation="open" profile="/{,usr/}sbin/dhclient" name="/proc/775/task/848/comm" pid=775 comm="dhclient" requested_mask="wr" denied_mask="wr" fsuid=0 ouid=0
[ 39.616480] audit: type=1400 audit(1626546618.403:83): apparmor="DENIED" operation="open" profile="/{,usr/}sbin/dhclient" name="/proc/775/task/849/comm" pid=775 comm="dhclient" requested_mask="wr" denied_mask="wr" fsuid=0 ouid=0
[ 39.616563] audit: type=1400 audit(1626546618.403:84): apparmor="DENIED" operation="open" profile="/{,usr/}sbin/dhclient" name="/proc/775/task/850/comm" pid=775 comm="dhclient" requested_mask="wr" denied_mask="wr" fsuid=0 ouid=0
[ 62.154604] audit: type=1400 audit(1626546640.939:85): apparmor="DENIED" operation="capable" profile="/usr/sbin/cups-browsed" pid=971 comm="cups-browsed" capability=23 capname="sys_nice"
[ 370.614154] aufs 5.4.3-20200302
[ 370.614638] aufs aufs_fill_super:918:mount[1790]: no arg
[ 370.744875] overlayfs: missing 'lowerdir'
[ 388.973010] audit: type=1400 audit(1626546967.759:86): apparmor="DENIED" operation="ptrace" profile="snap.docker.dockerd" pid=1905 comm="ps" requested_mask="read" denied_mask="read" peer="/{,usr/}sbin/dhclient"
[ 405.113288] Initializing XFRM netlink socket
[ 483.800276] rfkill: input handler disabled
[ 502.044283] audit: type=1400 audit(1626547080.831:91): apparmor="DENIED" operation="mknod" profile="/usr/share/hplip/systray.py" name="/var/crash/_usr_share_hplip_systray.py.1000.crash" pid=2732 comm="hp-systray" requested_mask="c" denied_mask="c" fsuid=1000 ouid=1000
[ 626.132953] perf: interrupt took too long (2512 > 2500), lowering kernel.perf_event_max_sample_rate to 79500
[ 951.554434] perf: interrupt took too long (3142 > 3140), lowering kernel.perf_event_max_sample_rate to 63500
[ 1251.050145] perf: interrupt took too long (3930 > 3927), lowering kernel.perf_event_max_sample_rate to 50750
启动需要那么长时间的原因是什么以及如何解决？
更多信息：
cat /etc/fstab 的输出：
# /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/sda1 during installation
UUID=7dd9bc28-9780-4a60-9f94-87c3471f2089 / ext4 errors=remount-ro 0 1
/swapfile none swap sw 0 0
sudo blkid 的输出：
/dev/sda1: UUID="7dd9bc28-9780-4a60-9f94-87c3471f2089" TYPE="ext4" PARTUUID="d19045a2-01"
/dev/loop0: TYPE="squashfs"
/dev/loop1: TYPE="squashfs"
/dev/loop2: TYPE="squashfs"
/dev/loop3: TYPE="squashfs"
/dev/loop4: TYPE="squashfs"
/dev/loop5: TYPE="squashfs"
/dev/loop6: TYPE="squashfs"
/dev/loop7: TYPE="squashfs"
/dev/sda2: UUID="a566bb53-bff0-452b-9eb8-5ae08eb31dd0" TYPE="ext4" PARTUUID="d19045a2-02"
/dev/sda5: UUID="17b4a94c-68db-418f-83be-4453f380a4d6" TYPE="ext4" PARTUUID="d19045a2-05"
/dev/loop8: TYPE="squashfs"
/dev/loop9: TYPE="squashfs"
/dev/loop10: TYPE="squashfs"
/dev/loop11: TYPE="squashfs"
/dev/loop12: TYPE="squashfs"
/dev/loop13: TYPE="squashfs"
/dev/loop14: TYPE="squashfs"
/dev/loop15: TYPE="squashfs"
/dev/loop16: TYPE="squashfs"
/dev/loop17: TYPE="squashfs"
/dev/loop18: TYPE="squashfs"
/dev/loop19: TYPE="squashfs"
/dev/loop20: TYPE="squashfs"
/dev/loop21: TYPE="squashfs"
/dev/loop22: TYPE="squashfs"
/dev/loop23: TYPE="squashfs"
/dev/loop24: TYPE="squashfs"
/dev/loop25: TYPE="squashfs"
/dev/loop26: TYPE="squashfs"
/dev/loop27: TYPE="squashfs"
/dev/loop28: TYPE="squashfs"
/dev/loop29: TYPE="squashfs"
/dev/loop30: TYPE="squashfs"
/dev/loop31: TYPE="squashfs"
systemd-analyze blame 的输出：
1min 15.451s apt-daily-upgrade.service
43.216s ifupdown-pre.service
41.231s dev-sda1.device
30.067s snapd.service
28.683s networkd-dispatcher.service
27.266s dev-loop28.device
25.981s udisks2.service
25.328s dev-loop31.device
24.464s dev-loop12.device
24.307s dev-loop27.device
24.008s accounts-daemon.service
23.806s dev-loop26.device
23.798s dev-loop23.device
23.590s dev-loop30.device
23.359s dev-loop29.device
23.130s dev-loop25.device
23.093s dev-loop13.device
22.859s networking.service
20.989s dev-loop22.device
20.909s dev-loop17.device
20.907s dev-loop24.device
20.905s dev-loop14.device
20.905s dev-loop11.device
19.782s dev-loop8.device
19.482s openvpnas.service
18.305s dev-loop9.device
18.304s dev-loop5.device
18.303s dev-loop6.device
18.301s dev-loop7.device
18.300s dev-loop16.device
18.297s dev-loop15.device
18.293s dev-loop19.device
16.610s dev-loop4.device
16.610s dev-loop2.device
16.609s dev-loop0.device
16.609s dev-loop1.device
16.607s dev-loop3.device
16.606s dev-loop10.device
16.603s dev-loop18.device
16.598s dev-loop20.device
16.597s dev-loop21.device
15.768s avahi-daemon.service
15.294s NetworkManager.service
15.178s polkit.service
14.492s switcheroo-control.service
14.484s thermald.service
14.430s systemd-logind.service
14.417s wpa_supplicant.service
13.653s winbind.service
12.544s systemd-journal-flush.service
11.046s grub-common.service
9.978s apport.service
8.960s gpu-manager.service
8.902s apache2.service
8.655s systemd-udevd.service
8.618s NetworkManager-wait-online.service
7.669s ModemManager.service
6.905s rsyslog.service
6.046s teamviewerd.service
4.932s apparmor.service
4.088s e2scrub_reap.service
3.825s colord.service
3.223s lm-sensors.service
3.081s snapd.apparmor.service
2.566s grub-initrd-fallback.service
2.531s lightdm.service
2.525s plymouth-quit-wait.service
2.514s systemd-sysctl.service
2.484s systemd-tmpfiles-setup.service
2.378s ssh.service
2.191s dns-clean.service
1.946s snap-audacity-756.mount
1.884s snap-audacity-857.mount
1.847s systemd-modules-load.service
1.818s snap-chromium-1637.mount
1.811s snap-chromium-1646.mount
1.809s fwupd.service
1.753s snap-core-11187.mount
1.728s snap-core-11316.mount
1.615s keyboard-setup.service
1.569s snapd.seeded.service
1.539s snap-core18-2066.mount
1.539s upower.service
1.522s snap-core18-2074.mount
1.487s systemd-random-seed.service
1.467s snap-core20-1026.mount
1.393s snap-docker-471.mount
1.325s snap-docker-796.mount
1.219s snap-gnome\x2d3\x2d26\x2d1604-102.mount
1.198s snap-gnome\x2d3\x2d26\x2d1604-104.mount
1.143s snap-gnome\x2d3\x2d28\x2d1804-145.mount
1.133s systemd-timesyncd.service
1.128s snap-gnome\x2d3\x2d28\x2d1804-161.mount
1.070s snap-gnome\x2d3\x2d34\x2d1804-66.mount
1.028s systemd-sysusers.service
1.005s snap-gnome\x2d3\x2d34\x2d1804-72.mount
889ms snap-gnome\x2d3\x2d38\x2d2004-39.mount
861ms systemd-tmpfiles-setup-dev.service
763ms snap-gnome\x2dsystem\x2dmonitor-160.mount
734ms snap-gnome\x2dsystem\x2dmonitor-163.mount
649ms snap-gtk2\x2dcommon\x2dthemes-13.mount
642ms [email protected]
610ms snap-gtk2\x2dcommon\x2dthemes-9.mount
564ms snap-gtk\x2dcommon\x2dthemes-1514.mount
553ms phpsessionclean.service
542ms snap-gtk\x2dcommon\x2dthemes-1515.mount
541ms systemd-udev-trigger.service
494ms snap-handbrake\x2djz-142.mount
438ms swapfile.swap
437ms systemd-backlight@backlight:acpi_video0.service
431ms snap-inkscape-9078.mount
412ms console-setup.service
404ms snap-inkscape-9090.mount
386ms systemd-remount-fs.service
320ms kerneloops.service
319ms systemd-update-utmp.service
314ms systemd-journald.service
283ms [email protected]
266ms ufw.service
263ms systemd-backlight@backlight:intel_backlight.service
251ms setvtrgb.service
249ms snap-losslesscut-66.mount
241ms snap-losslesscut-72.mount
233ms plymouth-read-write.service
225ms snap-snap\x2dstore-547.mount
1min 15.451s apt-daily-upgrade.service
1min 15.451s apt-daily-upgrade.service
43.216s ifupdown-pre.service
41.231s dev-sda1.device
30.067s snapd.service
28.683s networkd-dispatcher.service
27.266s dev-loop28.device
25.981s udisks2.service
25.328s dev-loop31.device
24.464s dev-loop12.device
24.307s dev-loop27.device
24.008s accounts-daemon.service
23.806s dev-loop26.device
23.798s dev-loop23.device
23.590s dev-loop30.device
23.359s dev-loop29.device
23.130s dev-loop25.device
23.093s dev-loop13.device
22.859s networking.service
20.989s dev-loop22.device
20.909s dev-loop17.device
1min 15.451s apt-daily-upgrade.service
43.216s ifupdown-pre.service
41.231s dev-sda1.device
30.067s snapd.service
28.683s networkd-dispatcher.service
27.266s dev-loop28.device
25.981s udisks2.service
25.328s dev-loop31.device
24.464s dev-loop12.device
24.307s dev-loop27.device
24.008s accounts-daemon.service
23.806s dev-loop26.device
23.798s dev-loop23.device
23.590s dev-loop30.device
23.359s dev-loop29.device
23.130s dev-loop25.device
23.093s dev-loop13.device
22.859s networking.service
20.989s dev-loop22.device
20.909s dev-loop17.device
20.907s dev-loop24.device
20.905s dev-loop14.device
20.905s dev-loop11.device
19.782s dev-loop8.device
19.482s openvpnas.service
18.305s dev-loop9.device
18.304s dev-loop5.device
18.303s dev-loop6.device
18.301s dev-loop7.device
18.300s dev-loop16.device
18.297s dev-loop15.device
18.293s dev-loop19.device
16.610s dev-loop4.device
16.610s dev-loop2.device
16.609s dev-loop0.device
16.609s dev-loop1.device
16.607s dev-loop3.device
16.606s dev-loop10.device
16.603s dev-loop18.device
16.598s dev-loop20.device
16.597s dev-loop21.device
15.768s avahi-daemon.service
15.294s NetworkManager.service
15.178s polkit.service
14.492s switcheroo-control.service
14.484s thermald.service
14.430s systemd-logind.service
14.417s wpa_supplicant.service
13.653s winbind.service
12.544s systemd-journal-flush.service
11.046s grub-common.service
9.978s apport.service
8.960s gpu-manager.service
8.902s apache2.service
8.655s systemd-udevd.service
8.618s NetworkManager-wait-online.service
7.669s ModemManager.service
6.905s rsyslog.service
6.046s teamviewerd.service
4.932s apparmor.service
4.088s e2scrub_reap.service
3.825s colord.service
3.223s lm-sensors.service
3.081s snapd.apparmor.service
2.566s grub-initrd-fallback.service
2.531s lightdm.service
2.525s plymouth-quit-wait.service
2.514s systemd-sysctl.service
2.484s systemd-tmpfiles-setup.service
2.378s ssh.service
2.191s dns-clean.service
1.946s snap-audacity-756.mount
1.884s snap-audacity-857.mount
1.847s systemd-modules-load.service
1.818s snap-chromium-1637.mount
1.811s snap-chromium-1646.mount
1.809s fwupd.service
1.753s snap-core-11187.mount
1.728s snap-core-11316.mount
1.615s keyboard-setup.service
1.569s snapd.seeded.service
1.539s snap-core18-2066.mount
1.539s upower.service
1.522s snap-core18-2074.mount
1.487s systemd-random-seed.service
1.467s snap-core20-1026.mount
1.393s snap-docker-471.mount
1.325s snap-docker-796.mount
1.219s snap-gnome\x2d3\x2d26\x2d1604-102.mount
1.198s snap-gnome\x2d3\x2d26\x2d1604-104.mount
1.143s snap-gnome\x2d3\x2d28\x2d1804-145.mount
1.133s systemd-timesyncd.service
1.128s snap-gnome\x2d3\x2d28\x2d1804-161.mount
1.070s snap-gnome\x2d3\x2d34\x2d1804-66.mount
1.028s systemd-sysusers.service
1.005s snap-gnome\x2d3\x2d34\x2d1804-72.mount
889ms snap-gnome\x2d3\x2d38\x2d2004-39.mount
861ms systemd-tmpfiles-setup-dev.service
763ms snap-gnome\x2dsystem\x2dmonitor-160.mount
734ms snap-gnome\x2dsystem\x2dmonitor-163.mount
649ms snap-gtk2\x2dcommon\x2dthemes-13.mount
642ms [email protected]
610ms snap-gtk2\x2dcommon\x2dthemes-9.mount
564ms snap-gtk\x2dcommon\x2dthemes-1514.mount
553ms phpsessionclean.service
542ms snap-gtk\x2dcommon\x2dthemes-1515.mount
541ms systemd-udev-trigger.service
494ms snap-handbrake\x2djz-142.mount
438ms swapfile.swap
437ms systemd-backlight@backlight:acpi_video0.service
431ms snap-inkscape-9078.mount
412ms console-setup.service
404ms snap-inkscape-9090.mount
386ms systemd-remount-fs.service
320ms kerneloops.service
319ms systemd-update-utmp.service
314ms systemd-journald.service
283ms [email protected]
266ms ufw.service
263ms systemd-backlight@backlight:intel_backlight.service
251ms setvtrgb.service
249ms snap-losslesscut-66.mount
241ms snap-losslesscut-72.mount
233ms plymouth-read-write.service
225ms snap-snap\x2dstore-547.mount
206ms snapd.socket
196ms snap-snap\x2dstore-542.mount
178ms dev-hugepages.mount
177ms dev-mqueue.mount
175ms sys-kernel-debug.mount
173ms sys-kernel-tracing.mount
167ms kmod-static-nodes.service
161ms pppd-dns.service
160ms hddtemp.service
152ms snap-pdftk-9.mount
121ms systemd-user-sessions.service
119ms wicd.service
115ms systemd-resolved.service
109ms shadowsocks.service
96ms plymouth-start.service
83ms rtkit-daemon.service
41ms [email protected]
19ms alsa-restore.service
13ms systemd-update-utmp-runlevel.service
8ms systemd-rfkill.service
6ms e2scrub_all.service
5ms sys-fs-fuse-connections.mount
4ms sys-kekernelkernelrnel-config.mount
快照列表的输出：
Name Version Rev Tracking Publisher Notes
audacity 3.0.2 857 latest/stable diddledan -
chromium 91.0.4472.114 1646 latest/stable canonical* -
core 16-2.51.1 11316 latest/stable canonical* core
core18 20210611 2074 latest/stable canonical* base
core20 20210429 1026 latest/stable canonical* base
docker 19.03.13 796 latest/stable canonical* -
gnome-3-26-1604 3.26.0.20210629 104 latest/stable/… canonical* -
gnome-3-28-1804 3.28.0-19-g98f9e67.98f9e67 161 latest/stable canonical* -
gnome-3-34-1804 0+git.3556cb3 72 latest/stable canonical* -
gnome-3-38-2004 0+git.3d25b9b 39 latest/stable canonical* -
gnome-system-monitor 40.1-2-ga819fb4b55 163 latest/stable/… canonical* -
gtk-common-themes 0.1-52-gb92ac40 1515 latest/stable canonical* -
gtk2-common-themes 0.1 13 latest/stable canonical* -
handbrake-jz 1.2.2 142 latest/stable jz -
inkscape 1.1-ce6663b3b7-2021-05-25 9090 latest/stable inkscape* -
losslesscut 3.34.3 72 latest/stable mifino -
pdftk 2.02-4 9 latest/stable smoser -
snap-store 3.38.0-64-g23c4c77 547 latest/stable/… canonical* -
cat etc/network/interfaces 的输出：
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto enp0s25
iface enp0s25 inet dhcp
cat /etc/netplan/*.yaml 的输出：
# Let NetworkManager manage all devices on this system
network:
version: 2
renderer: NetworkManager
free -h 的输出：
total used free shared buff/cache available
Mem: 3.6Gi 1.8Gi 550Mi 180Mi 1.3Gi 1.4Gi
Swap: 2.0Gi 15Mi 2.0Gi
/etc/fstab
# /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/sda1 during installation
UUID=7dd9bc28-9780-4a60-9f94-87c3471f2089 / ext4 errors=remount-ro 0 1
/swapfile none swap sw 0 0
磁盘截图：
答案1
笔记：您可能遇到多个问题。网络、Docker 层、Snap、sda1 和 VPN。
让我们首先检查您的文件系统...
- 以“试用 Ubuntu”模式启动 Ubuntu Live DVD/USB
terminal按Ctrl+ Alt+打开窗口T- 类型
sudo fdisk -l - 识别“Linux 文件系统”的 /dev/sdXX 设备名称
- 输入
sudo fsck -f /dev/sda1，替换sdXX为您之前找到的数字 sudo fsck -f /dev/sda2sudo fsck -f /dev/sda5fsck如果有错误则重复命令- 类型
reboot
/etc/网络/接口
注释掉以下行并重新启动...
# The primary network interface
auto enp0s25
iface enp0s25 inet dhcp
/交换文件
由于只有 4G RAM，2G 的 /swapfile 太小了。我们将它从 2G 改为 4G...
笔记：错误使用rm和dd命令可能会导致数据丢失。建议复制/粘贴。
在里面terminal...
sudo swapoff -a # turn off swap
sudo rm -i /swapfile # remove old /swapfile
sudo dd if=/dev/zero of=/swapfile bs=1M count=4096
sudo chmod 600 /swapfile # set proper file protections
sudo mkswap /swapfile # init /swapfile
sudo swapon /swapfile # turn on swap
free -h # confirm 4G RAM and 4G swap
sudo -H gedit /etc/fstab使用或编辑 /etc/fstab sudo pico /etc/fstab。
确认 /etc/fstab 中的此 /swapfile 行...并确认没有其他“交换”行...在此行中使用空格...确认没有制表符...
/swapfile none swap sw 0 0
reboot # reboot and verify operation
更新＃1：
重新安装了 Ubuntu。