Description

This article describes why shmlog_lock_holder.pid<>.lock files could be created in /var/tmp/ folder and, if such files exist, if any steps should be taken.

Symptoms

File(s) shmlog_lock_holder.pid<>.lock get created in /var/tmp/ folder, for example: 
-rw-r--r-- 1 root wheel 53420032 Jun 13 05:33 shmlog_lock_holder.pid14104.lock
-rw-r--r-- 1 root wheel 53420032 May 25 12:05 shmlog_lock_holder.pid14743.lock
-rw-r--r-- 1 root wheel 53415936 Jul  3 10:59 shmlog_lock_holder.pid33225.lock
-rw-r--r-- 1 root wheel 53415936 Jun 27 23:09 shmlog_lock_holder.pid37215.lock

Solution

Shared memory logging mechanism may trigger creation of shmlog_lock_holder.pid<>.lock file when one of processes tries to allocate more shared memory than is available. There is no impact, live core of the offending process gets saved as shmlog_lock_holder.pid<>.lock file. 

If shmlog_lock_holder.pid<>.lock is present in /var/tmp/ directory, please contact JTAC and provide this file for further analysis.

Modification History

2024-08-09 : Article Created