Is it possible to make Ubuntu 20.04 boot faster?

Question

I'm sorry if my question is rather newbie, because it is - but I've never bothered to tweak my Linux much. I've managed to get my Manjaro (not without some external help) cut boot time to 8-10s (by systemd-analyze) and I'd like to maybe try the same thing with Ubuntu but I am not sure what should I do and if it is possible. By all means it is not extremely slow but there is a major drawback on my nvme SSD since I've been using Manjaro which was up and ready in 10s and now it takes about 25s to get ready with Ubuntu. While the Manjaro was slow because of the grub timeout, Ubuntu has grub set to 0 by default - that one I've checked.

Here's my systemd-analyze and systemd-analyze blame - if anything else is needed I'll provide it:

systemd-analyze
Startup finished in 8.390s (firmware) + 4.976s (loader) + 2.131s (kernel) + 9.071s (userspace) = 24.570s 
graphical.target reached after 9.039s in userspace
systemd-analyze blame
7.076s NetworkManager-wait-online.service

5.821s plymouth-quit-wait.service

5.041s bolt.service

1.753s grub-common.service

1.727s apport.service

1.159s snapd.service

1.047s systemd-logind.service

1.032s networkd-dispatcher.service

 996ms accounts-daemon.service

 824ms udisks2.service

 595ms polkit.service

 590ms avahi-daemon.service

 563ms bluetooth.service

 539ms NetworkManager.service

 438ms switcheroo-control.service

 395ms dev-nvme0n1p2.device

 365ms ModemManager.service

 328ms thermald.service

 314ms gdm.service

 311ms wpa_supplicant.service

 300ms upower.service

 253ms grub-initrd-fallback.service

 242ms e2scrub_reap.service

 240ms gpu-manager.service

 224ms rsyslog.service

 224ms dev-loop1.device

 223ms dev-loop0.device

 184ms snap-snap\x2dstore-467.mount

 183ms snap-snapd-8542.mount

 182ms snap-gtk\x2dcommon\x2dthemes-1506.mount

 173ms user@1000.service

 170ms dev-loop2.device

 154ms pppd-dns.service

 128ms systemd-resolved.service

 127ms systemd-backlight@backlight:intel_backlight.service

 119ms alsa-restore.service

 118ms systemd-timesyncd.service

 106ms dev-loop4.device

 104ms systemd-user-sessions.service

 103ms swapfile.swap

 101ms snap-gnome\x2d3\x2d34\x2d1804-36.mount

(...)

And here's systemd-analyze critical-chain:

graphical.target @9.039s
└─multi-user.target @9.039s
  └─kerneloops.service @8.974s +63ms
    └─network-online.target @8.969s
      └─NetworkManager-wait-online.service @1.891s +7.076s
        └─NetworkManager.service @1.340s +539ms
          └─dbus.service @1.311s
            └─basic.target @1.232s
              └─sockets.target @1.232s
                └─snapd.socket @1.226s +5ms
                  └─sysinit.target @1.210s
                    └─systemd-backlight@backlight:intel_backlight.service @1.082s +127ms
                      └─system-systemd\x2dbacklight.slice @921ms
                        └─system.slice @433ms
                          └─-.slice @433ms

Answer 1

I am using a NVMe SSD to boot. And have 20.04 Kubuntu installed. I also change grub to 3 sec delay from default of 10 sec, just to have time to press a key if needed.

fred@z170-focal-k:~$ systemd-analyze
Startup finished in 2.667s (kernel) + 5.167s (userspace) = 7.834s 
graphical.target reached after 5.155s in userspace

Turned off NetworkManager-wait with systemctl:

systemctl disable NetworkManager-wait-online.service

https://forums.linuxmint.com/viewtopic.php?t=282437

Changed from quiet splash to noplymouth, will see boot process rather than Ubuntu logo. Sometimes you then can see what process is hanging system, also. Even though not using raid nor encryption, installing drivers supposedly helps.

sed -i '/GRUB_TIMEOUT=/ s/10/3/' /etc/default/grub
sed -i '/GRUB_CMDLINE_LINUX_DEFAULT/ s/"quiet splash"/"noplymouth"/' /etc/default/grub
sudo update-grub
sudo apt install libblockdev-crypto2 libblockdev-mdraid2, 

turned off printer when rebooting,

removed all snaps, prefer .debs for most apps

sudo apt autoremove --purge snapd

If UEFI firmware update not supported (yet) and no thunderbolt, one of my systems also does not have bluetooth, so I also uninstall that on that system only

sudo apt-get purge fwupd
systemctl status bolt
boltctl list
systemctl mask bolt.service
sudo apt-get autoremove blueman bluez-utils bluez bluetooth 

Many with slow boot issues have reinstalled an have a reference in fstab to a bad UUID. Best to confirm all UUIDs are correct.

lsblk -o name,fstype,size,label,mountpoint,uuid | egrep -v "^loop"
cat /etc/fstab

Only if swap partition & reformatted this could be wrong UUID.

 cat /etc/initramfs-tools/conf.d/resume

Be sure to mount partitions with noatime.

UUID=54029c4f-0cbe-413e-80ce-78a4995b0551 /   ext4 noatime,errors=remount-ro  0  1

More details:

slow boot boot 19.10 (tried almost everything)

What does NetworkManager-wait-online.service do?

Ubuntu 16.04 slow boot (apt-daily.service)

How to remove fwupd.service from boot?

Do I really need apt-daily.service and apt-daily-upgrade.service?

https://ubuntuforums.org/showthread.php?t=2436900&p=13932499#post13932499

Ubuntu 15.04 network manager causing slow boot