Overview

While trying to upgrade old Kerio Control 9.2.x installed on custom hardware, the following console error is displayed:

BUG: soft lockup - CPU #0 stuck for 22s!

The direct upgrade to the latest Kerio Control firmware is not working.

This 'soft lockup' can happen if the kernel is busy, working on a huge amount of objects which need to be scanned, freed, or allocated, respectively.

This article provides information on how to resolve such errors and upgrade your Kerio Control manually.

Solution

Kerio Control 9.3 and later drops support for 32-bit architecture. Please verify your software appliance's CPU is compatible with 64-bit architecture.

Also, 9.3 introduces swap support. Because of it, please consider a manual upgrade procedure from 9.2.x -> 9.2.9 -> 9.3.0 -> 9.3.5.

Note: older versions of Kerio Control can be downloaded through Kerio Software Archive.

If the lockup messages are still presented even after the upgrade, in some situations, increasing the time before these soft lockups are fired can improve the situation.

1. Access Kerio Control using the SSH console.
2. Increase watchdog_thresh parameter from default 10 to 20 value:
   cat /proc/sys/kernel/watchdog_thresh
echo 20 > /proc/sys/kernel/watchdog_thresh
cat /proc/sys/kernel/watchdog_thresh