Applications and Processes Crashing and Exiting Due to Lack of Available Virtual Memory also called Swap (Doc ID 2947406.1)

Last updated on APRIL 08, 2024

Applies to:

Symptoms

User processes use Swap also known as Virtual memory and when there isn't enough available swap to meet the application's requirements, applications can fail in unpredictable ways.  A process creates and uses virtual memory in different ways for different purposes.  For some uses swap is reserved and in those cases there isn't a risk of the swap being unavailable when it's needed, but swap isn't always reserved.    A process can grow it's heap in which case there is a risk that the additional swap needed might not be available which can cause failures.  Most problematic for a swap shortage is that a process does not reserve swap for it's thread stacks.  Thread stacks tend to only use a small fraction of the space available to them, but this can lead to extremely unpredictable failures when a system runs out of swap.

This document will help identify cases where a system’s lack of swap is causing processes to fail.

One of the most obvious signs of lack of swap disrupting processes is the following in messages:

… … genunix: [ID 328136 kern.warning] WARNING: No swap space to grow stack for pid {PID} ({Executable) in zone {Zone Number} ({Zone Name})

Also see: Understanding "no swap space to grow stack" Messages (Doc ID 1008068.1)

Messages may also include messages like:
… … genunix: [ID 163280 kern.notice] {Executable}: Cannot map /lib/sparcv9/ld.so.1
… … tmpfs: [ID 518458 kern.warning] WARNING: /system/volatile: File system full, swap space limit exceeded
… … svc.startd[14]: [ID 462725 daemon.warning] {Service}: Couldn't fork to execute method {Path/File}: Cannot allocate memory

If you have ‘global core dumps’ and ‘global core dump logging’ enabled (see man coreadm) , then you will also likely see batches of:
… … genunix: [ID 603404 kern.notice] NOTICE: core_log: {Executable}[{PID}] core dumped: {/path/file}

Also see: How to handle COREDIAG-8000-1V FMA events (Doc ID 2847388.1)

Messages may also show:

Changes

There may not be any configuration changes in which case it may be an increase in system load or something else which has increased the swap usage

Cause