Ubuntu 16.04: Speed up Ubuntu 16.04 boot time on VirtualBox

This article will describe improving boot time.


1 System environment and boot time before speed up

This article runs VirtualBox on OSX and use below spec.


CPU Core Number 1
Video Memory 128MB
Storage IDE DVD Drive + SATA 40GB HDD


Ubuntu 16.04 is installed by ubuntu-16.04-desktop-amd64.iso and formatted by LVM + ext4.

A boot time after installation is as below.

$ systemd-analyze
Startup finished in 9.372s (kernel) + 5.721s (userspace) = 15.093s

2 Change BIOS timeout

BIOS timeout of VirtualBox is about 3 seconds by default. "Adjusting the VirtualBox F12 BIOS Boot Prompt Timeout" explains how to change BIOs timeout. Change the minimum 1 for improving boot time, change 3000 when you need BIOS operation.

3 Add Floppy Controller

VirtualBox 5.0.20 r106931 may have a issue with bus for floppy. This issue is that bus controller always treats floppy be exists without adding floppy controller.

Linux kernel will know floppy with probe function and run init function for floppy. The init function will be failed, sleep and try again, which will cause boot time delay.

[    2.038893] sd 2:0:0:0: [sda] Attached SCSI disk
[    4.311960] floppy0: no floppy controllers found
[    4.312010] work still pending

Add floppy controller for making init function to be succeed. Add floppy controller can be done when Ubuntu 16.04 is shutdowned.

Settings -> Storage -> Adds new storage controller -> Add Floppy Controller


It decreased kernel boot time about 2 seconds.

$ systemd-analyze
Startup finished in 6.980s (kernel) + 5.235s (userspace) = 12.216s

4 Fix /etc/initramfs-tools/conf.d/resume

Activating LVM swap causes boot time delay.

$ sudo su -c 'echo RESUME=/dev/mapper/ubuntu--vg-swap_1 > \
$ sudo update-initramfs -u
$ sudo reboot

It decreased kernel boot time about 5 seconds.

$ systemd-analyze
Startup finished in 2.223s (kernel) + 5.999s (userspace) = 8.223s

5 Disable vboxadd-x11.service

vboxadd-x11.service uses CPU power but does nothing.

$ systemd-analyze blame | head
          2.795s vboxadd.service
          1.770s vboxadd-x11.service
          1.235s dev-mapper-ubuntu\x2d\x2dvg\x2droot.device
          1.035s networking.service
           930ms accounts-daemon.service
           819ms NetworkManager.service
           802ms avahi-daemon.service
           673ms systemd-logind.service
           590ms apport.service
           577ms grub-common.service

Disable vboxadd-x11.service.

$ sudo systemctl disable vboxadd-x11
$ sudo reboot

It decreased userland boot time about 1 second.

$ systemd-analyze
Startup finished in 2.165s (kernel) + 4.389s (userspace) = 6.555s

6 In case of 2 CPU cores

The systemd runs parallel and it improves userlan boot time.

$ systemd-analyze
Startup finished in 2.175s (kernel) + 2.837s (userspace) = 5.012s