Boot delays with 4.15.0-24 based kernels in images

[Philip Roche]

We (Canonical CPC) are seeing an issue with today's build of the bionic minimal cloud images. Boot stops at "Starting Initial cloud-init job (metadata service crawler)..." for nearly 5 minutes (booting on scalingstack and locally with kvm) this is with a new kernel, but otherwise no changes over the prior image.

Image (manifest and logs) exhibiting this behaviour @ https://private-fileshare.canonical.com/~philroche/bionic-minimal-20180703/

With server teams's help we have narrowed it down to "Synchronized to time server 91.189.91.157:123 (ntp.ubuntu.com)." taking over 4 minutes.

On Kamal's instruction we also tried linux-kvm 4.15.0-1013.13 and bionic GA linux (4.15.0-24.26). Both of which also exhibit this regression.

For reference: Kamal noted on IRC that the problem was possibly introduced in the GA kernel and is not specific to the kvm kernel.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1779961

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Kamal Mostafa (kamalmostafa)]

Problem also occurs in bionic GA linux (4.15.0-24.26) per Odd_Bloke; apparently introduced in that release.

[Michael Vogt (mvo)]

I suspect this is entropy related, i.e. something in the entropy handling changed which causes things that use random numbers during the boot to slow down. The snapd team is also affected by this bug (snapd startup during boot became slow but when people press keys, move mouse things get better).

[Marco (mqrco)]

Same Problem on Asus Ultrabook. Kernel 4.15.0-23 runns o.k. Kernel 4.15.0-24 extreme boot delay

[Philip Roche (philroche)]

The meta-packages have been rolled back and the fix is in progress of being applied and uploaded.