snapd.service在启动时需要相对较长时间才能运行，因此为了加快启动速度，我可以在启动完成后启动该服务吗？
结果如下systemd-analyze blame：
> systemd-analyze blame Sal 14 Ara 2021 14:58:50
29.098s plymouth-quit-wait.service >
17.111s dev-sda3.device >
16.480s snapd.service >
13.185s networkd-dispatcher.service >
11.886s udisks2.service >
8.401s accounts-daemon.service >
7.103s dev-loop3.device >
6.743s dev-loop22.device >
6.652s dev-loop15.device >
6.520s systemd-journal-flush.service >
6.420s dev-loop2.device >
6.385s dev-loop6.device >
6.367s avahi-daemon.service >
6.360s bluetooth.service >
6.356s NetworkManager.service >
6.307s polkit.service >
6.256s dev-loop1.device >
6.121s dev-loop13.device >
6.060s dev-loop21.device >
5.793s switcheroo-control.service >
5.786s thermald.service >
5.783s systemd-logind.service >
5.779s wpa_supplicant.service >
5.608s gpu-manager.service >
5.573s dev-loop17.device >
5.570s dev-loop9.device >
5.476s ModemManager.service >
5.262s dev-loop20.device >
5.243s dev-loop18.device >
5.104s dev-loop16.device >
5.049s dev-loop12.device >
5.035s dev-loop14.device >
4.958s dev-loop19.device >
4.730s dev-loop10.device >
4.539s plymouth-read-write.service >
4.410s dev-loop11.device >
4.209s dev-loop8.device >
3.959s zebra.service >
3.860s systemd-sysctl.service >
3.811s dev-loop4.device >
3.642s dev-loop7.device >
3.591s apport.service >
3.566s dev-loop5.device >
3.121s rsyslog.service >
3.119s e2scrub_reap.service >
3.075s snap-bare-5.mount >
2.958s dev-loop0.device >
2.799s snap-code-82.mount >
2.692s snap-code-83.mount >
2.678s snap-core-11798.mount >
2.610s snap-core-11993.mount >
2.499s gdm.service >
2.319s snap-core18-2246.mount >
2.179s tlp.service >
2.055s snap-core18-2253.mount >
2.039s fwupd.service >
2.009s virtualbox.service >
1.893s systemd-udevd.service >
1.774s systemd-tmpfiles-setup.service >
1.750s apparmor.service >
1.745s systemd-resolved.service >
1.692s secureboot-db.service >
1.633s colord.service >
1.434s snap-core20-1242.mount >
1.367s snap-core20-1270.mount >
1.344s ssh.service >
1.305s snap-gnome\x2d3\x2d34\x2d1804-72.mount >
1.270s packagekit.service >
1.270s snap-gnome\x2d3\x2d34\x2d1804-77.mount >
1.262s snapd.apparmor.service >
1.242s systemd-fsck@dev-disk-by\x2duuid-92804264\x2dc37f\x2d48cb\x2d8ec5\x2d49bc5be832fa>
1.234s systemd-tmpfiles-setup-dev.service >
1.183s systemd-random-seed.service >
1.143s nvidia-persistenced.service >
1.138s systemd-modules-load.service >
1.015s snap-gnome\x2d3\x2d38\x2d2004-76.mount >
967ms systemd-fsck@dev-disk-by\x2duuid-90BC\x2dAD77.service >
966ms upower.service >
957ms snap-gnome\x2d3\x2d38\x2d2004-87.mount >
943ms snap-gtk\x2dcommon\x2dthemes-1506.mount >
897ms snap-gtk\x2dcommon\x2dthemes-1519.mount >
802ms [email protected]
以及结果systemd-analyze critical-chain：
> systemd-analyze critical-chain 33.4s Sal 14 Ara 2021 14:59:39
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.
graphical.target @1min 6.867s
└─multi-user.target @1min 6.867s
└─snapd.seeded.service @48.059s +747ms
└─snapd.service @31.576s +16.480s
└─basic.target @30.982s
└─sockets.target @30.981s
└─snapd.socket @30.980s +1ms
└─sysinit.target @30.880s
└─snapd.apparmor.service @28.087s +1.262s
└─apparmor.service @26.334s +1.750s
└─local-fs.target @26.332s
└─run-user-1000-gvfs.mount @53.006s
└─run-user-1000.mount @44.989s
└─swap.target @24.765s
└─dev-disk-by\x2duuid-de61f134\x2d705a\x2d4c98\x2d89f7\x2d04a0b>
└─dev-disk-by\x2duuid-de61f134\x2d705a\x2d4c98\x2d89f7\x2d04a>
我正在使用 Ubuntu 20.04，其规格如下：
> lshw Sal 14 Ara 2021 18:21:47
WARNING: you should run this program as super-user.
hasan-nitro-an515-43
description: Computer
width: 64 bits
capabilities: smp vsyscall32
*-core
description: Motherboard
physical id: 0
*-memory
description: System memory
physical id: 0
size: 14GiB
*-cpu
product: AMD Ryzen 7 3750H with Radeon Vega Mobile Gfx
vendor: Advanced Micro Devices [AMD]
physical id: 1
bus info: cpu@0
size: 1352MHz
capacity: 2300MHz
width: 64 bits
capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp x86-64 constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb hw_pstate sme ssbd sev ibpb vmmcall sev_es fsgsbase bmi1 avx2 smep bmi2 rdseed adx smap clflushopt sha_ni xsaveopt xsavec xgetbv1 xsaves clzero irperf xsaveerptr arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif overflow_recov succor smca cpufreq
*-pci:0
description: Host bridge
product: Raven/Raven2 Root Complex
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 100
bus info: pci@0000:00:00.0
version: 00
width: 32 bits
clock: 33MHz
*-generic UNCLAIMED
description: IOMMU
product: Raven/Raven2 IOMMU
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 0.2
bus info: pci@0000:00:00.2
version: 00
width: 32 bits
clock: 33MHz
capabilities: cap_list
configuration: latency=0
*-pci:0
description: PCI bridge
product: Raven/Raven2 PCIe GPP Bridge [6:0]
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 1.1
bus info: pci@0000:00:01.1
version: 00
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:26 ioport:3000(size=4096) memory:c1000000-c1ffffff ioport:90000000(size=301989888)
*-display
description: 3D controller
product: TU117M [GeForce GTX 1650 Mobile / Max-Q]
vendor: NVIDIA Corporation
physical id: 0
bus info: pci@0000:01:00.0
version: a1
width: 64 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: driver=nvidia latency=0
resources: irq:75 memory:c1000000-c1ffffff memory:90000000-9fffffff memory:a0000000-a1ffffff ioport:3000(size=128)
*-pci:1
description: PCI bridge
product: Raven/Raven2 PCIe GPP Bridge [6:0]
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 1.2
bus info: pci@0000:00:01.2
version: 00
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:27 memory:c2800000-c28fffff
*-storage
description: Non-Volatile memory controller
product: BC501 NVMe Solid State Drive 512GB
vendor: SK hynix
physical id: 0
bus info: pci@0000:02:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: storage nvm_express bus_master cap_list
configuration: driver=nvme latency=0
resources: irq:44 memory:c2800000-c2803fff
*-nvme0
description: NVMe device
product: HFM256GDJTNG-8310A
physical id: 0
logical name: /dev/nvme0
version: 80002C00
serial: CY9CN00101150CE4Y
configuration: nqn=nqn.2014.08.org.nvmexpress:1c5c1c5cCY9CN00101150CE4Y HFM256GDJTNG-8310A state=live
*-namespace
description: NVMe namespace
physical id: 1
logical name: /dev/nvme0n1
*-pci:2
description: PCI bridge
product: Raven/Raven2 PCIe GPP Bridge [6:0]
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 1.6
bus info: pci@0000:00:01.6
version: 00
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:28 ioport:2000(size=4096) memory:c2700000-c27fffff
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:03:00.0
logical name: enp3s0
version: 25
serial: 08:97:98:8f:fa:bf
width: 64 bits
clock: 33MHz
capabilities: cap_list ethernet physical
configuration: broadcast=yes driver=r8169 latency=0 multicast=yes
resources: irq:34 ioport:2000(size=256) memory:c2704000-c2704fff memory:c2700000-c2703fff
*-pci:3
description: PCI bridge
product: Raven/Raven2 PCIe GPP Bridge [6:0]
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 1.7
bus info: pci@0000:00:01.7
version: 00
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:29 memory:c2000000-c21fffff
*-network
description: Wireless interface
product: QCA6174 802.11ac Wireless Network Adapter
vendor: Qualcomm Atheros
physical id: 0
bus info: pci@0000:04:00.0
logical name: wlp4s0
version: 32
serial: e4:aa:ea:50:6c:87
width: 64 bits
clock: 33MHz
capabilities: bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=ath10k_pci driverversion=5.11.0-41-generic firmware=WLAN.RM.4.4.1-00140-QCARMSWPZ-1 ip=192.168.1.46 latency=0 link=yes multicast=yes wireless=IEEE 802.11
resources: irq:79 memory:c2000000-c21fffff
*-pci:4
description: PCI bridge
product: Raven/Raven2 Internal PCIe GPP Bridge 0 to Bus A
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 8.1
bus info: pci@0000:00:08.1
version: 00
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:30 ioport:1000(size=4096) memory:c2300000-c26fffff ioport:b0000000(size=270532608)
*-display
description: VGA compatible controller
product: Picasso
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0
bus info: pci@0000:05:00.0
version: c1
width: 64 bits
clock: 33MHz
capabilities: vga_controller bus_master cap_list
configuration: driver=amdgpu latency=0
resources: irq:43 memory:b0000000-bfffffff memory:c0000000-c01fffff ioport:1000(size=256) memory:c2600000-c267ffff
*-multimedia:0
description: Audio device
product: Raven/Raven2/Fenghuang HDMI/DP Audio Controller
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0.1
bus info: pci@0000:05:00.1
version: 00
width: 32 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: driver=snd_hda_intel latency=0
resources: irq:82 memory:c2688000-c268bfff
*-generic
description: Encryption controller
product: Family 17h (Models 10h-1fh) Platform Security Processor
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 0.2
bus info: pci@0000:05:00.2
version: 00
width: 32 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: driver=ccp latency=0
resources: irq:71 memory:c2500000-c25fffff memory:c268c000-c268dfff
*-usb:0
description: USB controller
product: Raven USB 3.1
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 0.3
bus info: pci@0000:05:00.3
version: 00
width: 64 bits
clock: 33MHz
capabilities: xhci cap_list
configuration: driver=xhci_hcd latency=0
resources: irq:33 memory:c2400000-c24fffff
*-usb:1
description: USB controller
product: Raven USB 3.1
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 0.4
bus info: pci@0000:05:00.4
version: 00
width: 64 bits
clock: 33MHz
capabilities: xhci bus_master cap_list
configuration: driver=xhci_hcd latency=0
resources: irq:43 memory:c2300000-c23fffff
*-multimedia:1
description: Audio device
product: Family 17h (Models 10h-1fh) HD Audio Controller
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 0.6
bus info: pci@0000:05:00.6
version: 00
width: 32 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: driver=snd_hda_intel latency=0
resources: irq:45 memory:c2680000-c2687fff
*-pci:5
description: PCI bridge
product: Raven/Raven2 Internal PCIe GPP Bridge 0 to Bus B
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 8.2
bus info: pci@0000:00:08.2
version: 00
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:31 memory:c2200000-c22fffff
*-sata
description: SATA controller
product: FCH SATA Controller [AHCI mode]
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 0
bus info: pci@0000:06:00.0
version: 61
width: 32 bits
clock: 33MHz
capabilities: sata ahci_1.0 bus_master cap_list
configuration: driver=ahci latency=0
resources: irq:72 memory:c2200000-c22007ff
*-serial
description: SMBus
product: FCH SMBus Controller
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 14
bus info: pci@0000:00:14.0
version: 61
width: 32 bits
clock: 66MHz
configuration: driver=piix4_smbus latency=0
resources: irq:0
*-isa
description: ISA bridge
product: FCH LPC Bridge
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 14.3
bus info: pci@0000:00:14.3
version: 51
width: 32 bits
clock: 66MHz
capabilities: isa bus_master
configuration: latency=0
*-pci:1
description: Host bridge
product: Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 101
bus info: pci@0000:00:01.0
version: 00
width: 32 bits
clock: 33MHz
*-pci:2
description: Host bridge
product: Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 102
bus info: pci@0000:00:08.0
version: 00
width: 32 bits
clock: 33MHz
*-pci:3
description: Host bridge
product: Raven/Raven2 Device 24: Function 0
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 103
bus info: pci@0000:00:18.0
version: 00
width: 32 bits
clock: 33MHz
*-pci:4
description: Host bridge
product: Raven/Raven2 Device 24: Function 1
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 104
bus info: pci@0000:00:18.1
version: 00
width: 32 bits
clock: 33MHz
*-pci:5
description: Host bridge
product: Raven/Raven2 Device 24: Function 2
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 105
bus info: pci@0000:00:18.2
version: 00
width: 32 bits
clock: 33MHz
*-pci:6
description: Host bridge
product: Raven/Raven2 Device 24: Function 3
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 106
bus info: pci@0000:00:18.3
version: 00
width: 32 bits
clock: 33MHz
configuration: driver=k10temp
resources: irq:0
*-pci:7
description: Host bridge
product: Raven/Raven2 Device 24: Function 4
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 107
bus info: pci@0000:00:18.4
version: 00
width: 32 bits
clock: 33MHz
*-pci:8
description: Host bridge
product: Raven/Raven2 Device 24: Function 5
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 108
bus info: pci@0000:00:18.5
version: 00
width: 32 bits
clock: 33MHz
*-pci:9
description: Host bridge
product: Raven/Raven2 Device 24: Function 6
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 109
bus info: pci@0000:00:18.6
version: 00
width: 32 bits
clock: 33MHz
*-pci:10
description: Host bridge
product: Raven/Raven2 Device 24: Function 7
vendor: Advanced Micro Devices, Inc. [AMD]
physical id: 10a
bus info: pci@0000:00:18.7
version: 00
width: 32 bits
clock: 33MHz
*-pnp00:00
product: PnP device PNP0c02
physical id: 2
capabilities: pnp
configuration: driver=system
*-pnp00:01
product: PnP device PNP0b00
physical id: 3
capabilities: pnp
configuration: driver=rtc_cmos
*-pnp00:02
product: PnP device FUJ7401
physical id: 4
capabilities: pnp
configuration: driver=i8042 kbd
*-pnp00:03
product: PnP device PNP0c02
physical id: 5
capabilities: pnp
configuration: driver=system
*-pnp00:04
product: PnP device PNP0c01
physical id: 6
capabilities: pnp
configuration: driver=system
WARNING: output may be incomplete or inaccurate, you should run this program as super-user
答案1
您确实可以延迟 snapd 的启动。启动后，您将无法启动 snap 应用程序，直到守护进程加载完毕。但是，您最多可以将启动时间缩短不到半秒。
答案2
“责备”中的时间并不表明有任何长时间的等待。对于像 i3 这样的带有普通硬盘的系统来说，这似乎是正常的。
仅列举其中几项服务...
参见networkd-dispatcher.serviceKubuntu 启动速度极慢（18.04 LTS）
为了dev-sda3.device确保时间不包括文件系统检查systemctl status dev-sda3.device。
plymouth-quit-wait.service：在启动过程开始时加载启动徽标，并然后等待启动过程完成，以便卸载启动画面。因此，这 29 架飞机大多在等待其他服务。
bluetooth.service当您不使用 BT 时...请禁用它。