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I have installed Ubuntu 16.04 ony Lenovo 3g hhd, 4 g ram. It all went smoothly until it gets stuck on the boot process with "random crng init done". Help with this issue is greatly appreciated.

Victor Sanchez
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6 Answers6

5

It's a kernel bug that can happen with different kernel.

"apt-get install rng-tools" run as root in a terminal should work.

Giulio G
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  • This also helped me on Ubuntu 18.04 when the kernel was getting stuck at "random: crng init done" for 90 sec before boot would continue. I have no idea if the following is really necessary, but after installing rng-tools, I also updated initramfs and grub: sudo update-initramfs -u and sudo update-grub. More info on rng-tools is here: https://wiki.archlinux.org/index.php/Rng-tools – MDMower Jul 08 '18 at 20:42
  • tried running sudo apt-get install rng-tools but it showing E: Package 'rng-tools' has no installation candidate error – M.A.K. Ripon Apr 15 '20 at 16:31
2

This may happen after deleting the swap partition

Hanging before kernel: random: crng init done may happen after deleting a swap partition.

If a swap partition is deleted, the file /etc/initramfs-tools/conf.d/resume should be either completely empty or read RESUME=. Delete any UUID number. RESUME=NONE is not valid.

$ sudo nano /etc/initramfs-tools/conf.d/resume

The initial RAM filesystem requires updating for these changes to take effect:

$ sudo update-initramfs -u
Community
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Serge Stroobandt
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1

At boot, the kernel waits for mouse movements to initialize the random number generator.

Kernel messages on boot: 

sudo dmesg | less

The problem message: 

kernel: random: crng init done

The solution: 

sudo apt install haveged
sudo systemctl enable haveged
Stephen Rauch
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virusmxa
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    What is your basis that the kernel waits for mouse movements to init the random number generator? There are cases where this may not be the cause (non-graphical environments for example where there is no GUI or Mouse interaction) (and I've had this happen twice in the past few months on low-spec servers) – Thomas Ward Aug 10 '18 at 20:22
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I faced the same issue, and the fixes suggested here did not work. It was a broken link to a swap partition on my USB. It can be fixed using update-initramfs -uk all More details can be found at https://askubuntu.com/a/1084738/881810

Dushyant MAHADIK
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1

For anyone searching for this in the future, I ran in to this issue when trying to install Ubuntu 20.04 on to an old HP TouchSmart TM2-1070us laptop with an Intel Core 2 Duo U7300 CPU.

Just trying to boot the live CD would have the system stall after "random crng init done". No amount of waiting would get past it.

I was really stumped for a while but accidentally found that the issue, in my case, was caused by having "Virtualization Technology" enabled in the BIOS. By default it is disabled. I have no idea why this causes it but as long as I leave it disabled, Ubuntu boots and installs fine.

tinfever
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0

This issue can also be caused by combining non-related btrfs partitions on 1 system and booting with a kernel and init-system that doesn't know about this.

I had a system with a disk for my data and another one for my OS. Both used btrfs and although the system worked fine, I couldn't boot from a USB-stick. After (physically) detaching the data-disk it booted fine from USB.

Depending on what you want to achieve and how much time you want to spend on it there are multiple solutions available if your are in a similar situation. From easy to hard:

  • Don't boot from any other medium (ignoring the problem)
  • Backup your data of the extra btrfs-partition, overwrite the partition with another type of filesystem (e.g. ext4) and place your data back on this new filesystem.
  • Merge the 2 btrfs partitions into 1 filesystem. This can take a lot of work, and it's easy to make a mistake here. Double-check the newest version of the btrfs docs before you do this.
Garo
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