在我的桌面上（配备全新的 i3、8Gb DDR4 和安装在 SSD 上的 Ubuntu），我在 Ubuntu 上花费了很长时间。
$ systemd-analyze
Startup finished in 6.612s (kernel) + 6min 39.443s (userspace) = 6min 46.055s
我在之后发现了这些行journalctl -b：
janv. 28 15:31:15 PC-guillaume systemd[1]: Started LSB: AppArmor initialization.
janv. 28 15:31:15 PC-guillaume systemd[1]: Starting Raise network interfaces...
janv. 28 15:31:15 PC-guillaume kernel: input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card0/input9
janv. 28 15:31:15 PC-guillaume kernel: input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card0/input10
janv. 28 15:31:15 PC-guillaume kernel: input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card0/input11
janv. 28 15:31:15 PC-guillaume systemd[1]: Reached target Sound Card.
janv. 28 15:31:15 PC-guillaume systemd[1]: Started Raise network interfaces.
janv. 28 15:31:15 PC-guillaume systemd[1]: Stopped NVIDIA Persistence Daemon.
janv. 28 15:31:19 PC-guillaume kernel: usb 1-4: 1:1: cannot set freq 192000 (v2): err -110
janv. 28 15:31:19 PC-guillaume kernel: usb 1-4: cannot get ctl value: req = 0x83, wValue = 0x201, wIndex = 0xa00, type = 4
janv. 28 15:31:19 PC-guillaume kernel: usb 1-4: 10:0: cannot get min/max values for control 2 (id 10)
janv. 28 15:31:19 PC-guillaume kernel: usb 1-4: cannot get ctl value: req = 0x83, wValue = 0x200, wIndex = 0xa00, type = 4
janv. 28 15:31:19 PC-guillaume kernel: usb 1-4: 10:0: cannot get min/max values for control 2 (id 10)
janv. 28 15:31:19 PC-guillaume kernel: usbcore: registered new interface driver snd-usb-audio
janv. 28 15:31:19 PC-guillaume systemd-udevd[338]: Process '/usr/sbin/alsactl -E HOME=/run/alsa restore 1' failed with exit code 99.
janv. 28 15:32:44 PC-guillaume systemd[1]: dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.device: Job dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.device/start timed out.
janv. 28 15:32:44 PC-guillaume systemd[1]: Timed out waiting for device dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.device.
janv. 28 15:32:44 PC-guillaume systemd[1]: Dependency failed for /dev/disk/by-uuid/4baae2c1-29fa-4d67-9d0e-2499a6e710c9.
janv. 28 15:32:44 PC-guillaume systemd[1]: Dependency failed for Swap.
janv. 28 15:32:44 PC-guillaume systemd[1]: swap.target: Job swap.target/start failed with result 'dependency'.
janv. 28 15:32:44 PC-guillaume systemd[1]: dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.swap: Job dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.swap/start failed with result 'dependency
janv. 28 15:32:44 PC-guillaume systemd[1]: dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.device: Job dev-disk-by\x2duuid-4baae2c1\x2d29fa\x2d4d67\x2d9d0e\x2d2499a6e710c9.device/start failed with result 'timeou
janv. 28 15:32:44 PC-guillaume systemd[1]: Reached target System Initialization.
然后我得到了几百个这样的：
kernel: usb 1-4: 1:1: usb_set_interface failed (-71)
还有这个：
janv. 28 15:32:50 PC-guillaume pulseaudio[1494]: [pulseaudio] module-alsa-card.c: Failed to find a working profile.
janv. 28 15:32:50 PC-guillaume pulseaudio[1494]: [pulseaudio] module.c: Failed to load module "module-alsa-card" (argument: "device_id="1" name="usb-MICROMEGA_MICROMEGA_MYDAC_0000-00" card_name="alsa_card.usb-MICROMEGA_MICROMEGA_MYD
janv. 28 15:32:50 PC-guillaume kernel: usb 1-4: 1:1: usb_set_interface failed (-71)
我有一个 Micromega USB DAC，我在 Ubuntu 上安装它作为声卡使用，它似乎是我的问题的根源，但我不知道该怎么办......
任何想法 ？
非常感谢您的帮助 ！