Slow boot up after upgrade from 14.04 to 16.04

[michaelbr]

Greetings all:
I just upgraded Ubuntu from 14.04 to 16.04, my system is as follows:
product: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz
vendor: Intel Corp.
physical id: 1
bus info: cpu@0
size: 1238MHz
capacity: 2400MHz
width: 64 bits

After the upgrade I got an "shim-signed" error, and also the boot time is higher than 14.04, how or what adjustment can I do to speed up the boot time?
ps: the shim-signed error was fixed by using the following instructions:
sudo apt-get purge grub\*
sudo apt-get install grub-efi
sudo apt-get autoremove
sudo update-grub

[transit72]

I have the same problem with my Dell laptop:
Dell Inspiron 3542
CPU: Intel® Core™ i3-4005U CPU @ 1.70GHz × 4
Memory: 4GB
HDD: 220GB
Additional Drivers: 271567

I had Ubuntu 14.04 (in dual boot with Windows 8.1) and it would boot in less than a minute! A few weeks ago I decided to upgrade it to 16.04 and since then it takes about 4 minutes to boot :(
systemd-analyze says:

Startup finished in 7.235s (firmware) + 5.170s (loader) + 3.778s (kernel) + 3min 34.953s (userspace) = 3min 51.138s
and systemd-analyze blame gives:

3min 346ms powerd.service
26.801s NetworkManager-wait-online.service
23.279s networking.service
21.081s click-system-hooks.service
19.512s snapd.firstboot.service
15.699s systemd-user-sessions.service
15.698s rsyslog.service
15.698s iio-sensor-proxy.service
9.130s nmbd.service
9.114s winbind.service
9.045s dev-sda7.device
8.570s samba-ad-dc.service
8.014s irqbalance.service
7.915s speech-dispatcher.service
7.893s apport.service
7.613s grub-common.service
7.602s ondemand.service
4.380s accounts-daemon.service
3.613s apparmor.service
3.535s systemd-fsck@dev-disk-by\x2duuid-C0EE\x2d8DE3.service
3.227s NetworkManager.service
2.584s plymouth-start.service
2.454s gpu-manager.service
1.759s user@1000.service
1.733s systemd-udevd.service
1.688s keyboard-setup.service
1.527s systemd-tmpfiles-setup-dev.service
1.279s polkitd.service
1.227s thermald.service
1.104s avahi-daemon.service
1.056s systemd-timesyncd.service
956ms bluetooth.service
934ms dev-mqueue.mount
931ms dev-hugepages.mount
904ms console-setup.service
728ms systemd-rfkill.service
712ms systemd-modules-load.service
709ms lightdm.service
694ms plymouth-quit-wait.service
658ms systemd-logind.service
648ms systemd-backlight@backlight:intel_backlight.service
620ms ofono.service
547ms upower.service
546ms systemd-journald.service
541ms alsa-restore.service
541ms sys-kernel-debug.mount
537ms binfmt-support.service
434ms udisks2.service
419ms smbd.service
408ms dev-sda8.swap
389ms ufw.service
384ms systemd-tmpfiles-setup.service
323ms systemd-sysctl.service
302ms systemd-update-utmp.service
297ms systemd-backlight@leds:dell::kbd_backlight.service
295ms boot-efi.mount
273ms proc-sys-fs-binfmt_misc.mount
247ms colord.service
221ms dns-clean.service
205ms systemd-udev-trigger.service
175ms pppd-dns.service
155ms resolvconf.service
151ms rtkit-daemon.service
147ms systemd-localed.service
127ms kmod-static-nodes.service
123ms wpa_supplicant.service
112ms systemd-hostnamed.service
83ms snapd.socket
76ms systemd-journal-flush.service
74ms plymouth-read-write.service
70ms systemd-tmpfiles-clean.service
66ms systemd-remount-fs.service
65ms systemd-random-seed.service
59ms sys-fs-fuse-connections.mount
53ms setvtrgb.service
42ms openvpn.service
24ms rc-local.service
21ms systemd-update-utmp-runlevel.service
14ms snapd.boot-ok.service
9ms ureadahead-stop.service

Is there a way to speed up this powerd.service?

[transit72]

After googling around I found this https://bugs.launchpad.net/powerd/+bug/1443278. So I went ahead and disabled the powerd.service and also removed it completely from my system. Boot time has greatly improved, but I would still like to know how it came to be installed in my system in the first place. Could it be a leftover from 14.04 that wasn't removed or did it come with the upgrade to 16.04? Any ideas anyone?