提高性能和减少启动时间的技巧 - Ubuntu 21.04

我完成了 Ubuntu 21.04 的安装。我选择了超过 20.04 LTS 的版本，因为它本身不支持我的 wifi 适配器。我在不同的发行版中跳来跳去，试图找到启动时间最快的发行版。到目前为止，Xubuntu 21.04 是启动速度最快的版本，但是有问题，我不喜欢 Xfce。我试图减少启动时间，不是因为挑剔或“灵活”，而是因为我经营在线业务，每一分钟都很重要。如果这有帮助，这是我的电脑规格：

• 2TB 5400 转 SATA
• 12GB DDR4-2400 SDRAM
• 802.11b/g/n/ac Wifi 和蓝牙 4.2 组合 (Realtek RTL8821ce)
• Ubuntu 21.04 双启动与 Windows 10
• AMD Athlon Gold 3150U（2.4GHz，最高 3.3 Ghz，1 MB L2 高速缓存，2 核），带 AMD Radeon 显卡

输出systemd-analyze blame：

1min 27.453s snapd.seeded.service
1min 17.267s plymouth-quit-wait.service
     16.950s networkd-dispatcher.service
     14.426s snapd.service
     10.870s NetworkManager-wait-online.service
     10.163s dev-sda6.device
      8.543s udisks2.service
      7.301s apparmor.service
      6.341s NetworkManager.service
      6.310s ModemManager.service
      6.216s accounts-daemon.service
      4.649s polkit.service
      4.227s thermald.service
      3.986s bluetooth.service
      3.986s avahi-daemon.service
      3.898s wpa_supplicant.service
      3.878s power-profiles-daemon.service
      3.734s apport.service
      3.699s switcheroo-control.service
      3.689s systemd-logind.service
      3.435s cups.service
      3.431s e2scrub_reap.service
      3.323s dev-loop2.device

输出systemd-analyze critical-chain：

graphical.target @2min 8.160s
└─multi-user.target @2min 8.160s
  └─snapd.seeded.service @40.705s +1min 27.453s
    └─snapd.service @26.271s +14.426s
      └─basic.target @25.806s
        └─sockets.target @25.805s
          └─snapd.socket @25.804s +1ms
            └─sysinit.target @25.558s
              └─snapd.apparmor.service @22.981s +2.577s
                └─apparmor.service @15.678s +7.301s
                  └─local-fs.target @15.676s
                    └─run-snapd-ns-snap\x2dstore.mnt.mount @1min 7.986s
                      └─run-snapd-ns.mount @1min 6.169s
                        └─local-fs-pre.target @6.251s
                          └─systemd-tmpfiles-setup-dev.service @6.201s +50ms
                            └─systemd-sysusers.service @4.618s +1.581s
                              └─systemd-remount-fs.service @4.243s +289ms
                                └─systemd-journald.socket @4.071s
                                  └─-.mount @4.063s
                                    └─-.slice @4.063s

输出systemd-analyze：

Startup finished in 5.921s (firmware) + 6.908s (loader) + 7.139s (kernel) + 2min 8.173s (userspace) = 2min 28.143s 
graphical.target reached after 2min 8.160s in userspace

对于@heynnema：

输出snap list：

Name                Version             Rev    Tracking         Publisher   Notes
core18              20210309            1997   latest/stable    canonical✓  base
core20              20210319            975    latest/stable    canonical✓  base
gnome-3-34-1804     0+git.3556cb3       66     latest/stable/…  canonical✓  -
gtk-common-themes   0.1-52-gb92ac40     1515   latest/stable/…  canonical✓  -
snap-store          3.38.0-59-g494f078  518    latest/stable/…  canonical✓  -
snapd               2.50                11841  latest/stable    canonical✓  snapd
whitesur-gtk-theme  3.4                 74     latest/stable    spider623   -

输出free -h：

 total        used        free      shared  buff/cache   available
Mem:          9.7Gi       1.8Gi       785Mi        70Mi       7.1Gi       7.5Gi
Swap:         2.0Gi       1.0Mi       2.0Gi

输出sysctl vm.swappiness：

vm.swappiness = 60

输出sudo lshw -C memory：

  *-firmware                
       description: BIOS
       vendor: AMI
       physical id: 0
       version: F.57
       date: 09/28/2020
       size: 64KiB
       capacity: 16MiB
       capabilities: pci upgrade shadowing cdboot bootselect edd int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer acpi usb smartbattery biosbootspecification netboot uefi
  *-memory
       description: System Memory
       physical id: 9
       slot: System board or motherboard
       size: 12GiB
     *-bank:0
          description: SODIMM DDR4 Synchronous Unbuffered (Unregistered) 3200 MHz (0.3 ns)
          product: HMA851S6DJR6N-XN
          vendor: Hynix
          physical id: 0
          serial: 22691E37
          slot: Bottom - Slot 1 (left)
          size: 4GiB
          width: 64 bits
          clock: 3200MHz (0.3ns)
     *-bank:1
          description: SODIMM DDR4 Synchronous Unbuffered (Unregistered) 2667 MHz (0.4 ns)
          product: AO1P26KC8T1-BXPS
          vendor: A-DATA Technology
          physical id: 1
          serial: 4FB00000
          slot: Bottom - Slot 2 (right)
          size: 8GiB
          width: 64 bits
          clock: 2667MHz (0.4ns)
  *-cache:0
       description: L1 cache
       physical id: b
       slot: L1 - Cache
       size: 192KiB
       capacity: 192KiB
       clock: 1GHz (1.0ns)
       capabilities: pipeline-burst internal write-back unified
       configuration: level=1
  *-cache:1
       description: L2 cache
       physical id: c
       slot: L2 - Cache
       size: 1MiB
       capacity: 1MiB
       clock: 1GHz (1.0ns)
       capabilities: pipeline-burst internal write-back unified
       configuration: level=2
  *-cache:2
       description: L3 cache
       physical id: d
       slot: L3 - Cache
       size: 4MiB
       capacity: 4MiB
       clock: 1GHz (1.0ns)
       capabilities: pipeline-burst internal write-back unified
       configuration: level=3

如果您需要更多输出，我将在下面应用编辑。任何帮助都会很棒。谢谢大家，祝大家有个愉快的一天！