Bug ID 2452601: Some out-of-memory messages in the LTM log file use a non-standard format and are not sent to remote log servers

Last Modified: Aug 06, 2026

Affected Product(s):
BIG-IP TMOS(all modules)

Known Affected Versions:
21.1.0, 21.1.0.1

Opened: Aug 06, 2026

Severity: 3-Major

Symptoms

Messages about out-of-memory monitoring appear in the /var/log/ltm file in a non-standard format. These lines begin with a date in MM/DD/YYYY HH:MM:SS form and omit the host name, process name, process identifier, severity, and message identifier that other lines contain. One such message is written every time a service starts or restarts, even when no out-of-memory event has occurred. For example: 08/05/2026 10:58:26 Checking for OOM kills in the last 5 seconds for service: big3d

Impact

The affected messages do not follow standard log file formatting, are not forwarded to remote log servers, and cannot be matched by log filters. On a system where a service restarts repeatedly, these messages can make up a significant portion of the /var/log/ltm file.

Conditions

-- A service starts or restarts, including during normal system startup. -- Viewing the /var/log/ltm file, or forwarding it to a remote log server.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips