Undocumented change in Jamf Pro 11.11 limits policy logs

In Jamf’s November 2024 Jamf Pro 11.11 update Jamf silently added in a 25 KB limit to policy log output. This will limit the your ability to troubleshoot scripts that fail to run with an output more than 25 KB.

Jamf support notes that this is to prevent “server degradation”. There is no public documentation on the new limitation, nor is it included in the Jamf Pro 11.11 release notes. Jamf’s suggestion is to modify scripts to limit output or send any additional data to a local log file instead.

Jamf Premium cloud customers can request this limit be increased.

Credit to Eric Carr of Mann Consulting for identifying this issue.

Testing

Testing this is quite simple, create a policy that uses this script which outputs ~27 bytes of data 1,000 times:

#!/bin/zsh

for i in {1..1000}; do
  echo "ThisStringIsAbout25Bytes $i"
done

Run the policy and check the log output. As shown in the image below you’ll see the log output is truncated at 25KB with …Output Truncated…

Next steps

Unless you’re on cloud premiums your options are limited, but include:

• Setup external logging to Datadog or Splunk.
• Rewrite the log files located in /Library/Application Support/JAMF/tmp/ before Jamf submits them.
• Reduce your logging statements in scripts.