Ubuntu 22.04机械硬盘(HDD)开机速度优化咨询

Hey there! I totally get wanting to speed up that boot time on your HDD—1 minute 31 seconds does feel sluggish, especially since your kernel loads up pretty fast (only 8 seconds!). Let’s dive into your systemd-analyze output and walk through actionable tweaks you can try.

First, here’s the breakdown you shared:

Boot Time Summary #

systemd-analyze

Startup finished in 8.061s (kernel) + 1min 23.131s (userspace) = 1min 31.192s
graphical.target reached after 1min 23.055s in userspace

Top Time-Consuming Services #

systemd-analyze blame

42.635s plymouth-quit-wait.service
23.877s systemd-journal-flush.service
22.750s networkd-dispatcher.service
20.374s snapd.service
19.755s NetworkManager-wait-online.service
14.015s udisks2.service
13.017s apache2.service
12.189s dev-sda2.device
11.926s ModemManager.service
11.647s cups.service
10.216s dev-loop15.device
9.726s dev-loop5.device
9.033s gdm.service
8.706s accounts-daemon.service
7.684s NetworkManager.service
7.063s snapd.seeded.service
5.838s dev-loop3.device
5.807s dev-loop14.device
5.784s dev-loop11.device
5.781s dev-loop16.device
5.761s dev-loop10.device
5.522s power-profiles-daemon.service
5.440s polkit.service
5.150s dev-loop12.device
5.128s dev-loop13.device
5.111s dev-loop17.device
5.072s dev-loop6.device
4.961s dev-loop9.device
4.926s dev-loop8.device
4.878s dev-loop2.device
4.806s dev-loop0.device
4.540s avahi-daemon.service
4.538s bluetooth.service
4.108s thermald.service
3.806s switcheroo-control.service
3.799s systemd-logind.service
3.775s wpa_supplicant.service
3.180s dev-loop4.device
2.733s systemd-resolved.service
2.705s dev-loop7.device
2.644s gpu-manager.service
2.240s systemd-tmpfiles-setup.service
2.212s secureboot-db.service
2.179s rsyslog.service

Actionable Optimizations #

Let’s tackle the biggest culprits first:

• plymouth-quit-wait.service (42s+): This service waits for the boot splash screen to exit, which is a massive bottleneck on HDDs. Disable it with:

  sudo systemctl disable plymouth-quit-wait.service
  

  You’ll still see the boot splash, but the system won’t hang around waiting for it to close.

• NetworkManager-wait-online.service (19s+): This pauses boot until your network is fully connected. If you don’t have critical services that need internet right at startup, disable it:

  sudo systemctl disable NetworkManager-wait-online.service
  

  Your network will still connect automatically after boot—this just stops the system from waiting for it.

• systemd-journal-flush.service (23s+): This flushes system logs to your HDD on boot. To speed this up, adjust the journal configuration:

  1. Open /etc/systemd/journald.conf with a text editor (e.g., sudo nano /etc/systemd/journald.conf)
  2. Uncomment the Storage line and change it to Storage=volatile (this keeps logs in RAM, so they’ll clear on reboot—great if you don’t need long-term logs)
  3. Or, if you want to keep logs, uncomment SystemMaxUse and set a reasonable limit (like SystemMaxUse=100M) to reduce the data written on boot.
  4. Save the file and run sudo systemctl restart systemd-journald

• networkd-dispatcher.service (22s+): This is for systemd-networkd, but you’re using NetworkManager (seen in your output). You can safely disable this service:

  sudo systemctl disable networkd-dispatcher.service
  

• snapd.service & snapd.seeded.service (20s + 7s): Snap apps mount multiple loop devices (all those dev-loop* entries in your blame list), which is slow on HDDs.

  • First, uninstall any Snap apps you don’t use (run snap list to see installed ones, then sudo snap remove <app-name>)
  • If you still use Snaps, disable the seeded service (it waits for Snap to finish initializing):

    sudo systemctl disable snapd.seeded.service
    

• apache2.service (13s): If you don’t need your web server to start automatically on boot, disable it:

  sudo systemctl disable apache2.service
  

  You can start it manually when needed with sudo systemctl start apache2.service.

• ModemManager.service (11s+): If you don’t use a dial-up modem or mobile broadband, disable this:

  sudo systemctl disable ModemManager.service
  

• cups.service (11s+): If you don’t have a printer connected, disable the printing service:

  sudo systemctl disable cups.service
  

Additional HDD-Specific Tweaks #

• Optimize disk mount options: Edit your /etc/fstab file (with sudo nano /etc/fstab) and add noatime to your root partition (dev-sda2) line. This disables writing access times to the disk, reducing unnecessary HDD activity. The line should look something like:

  UUID=xxxxxx / ext4 errors=remount-ro,noatime 0 1
  

• Defragment the disk: While ext4 handles fragmentation automatically, you can run a manual defrag on your root partition to speed up reads/writes:

  sudo e4defrag /dev/sda2
  

  Note: This may take a while, so run it when you don’t need to use the system.

After making these changes, reboot and run systemd-analyze again to see the improvement—you should notice a significant drop in boot time!

备注：内容来源于stack exchange，提问作者user1566092