How to simulate "out of memory issue" in linux?

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by emie , in category: General Help , 6 months ago

How to simulate "out of memory issue" in linux?

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2 answers

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by ethelyn , 6 months ago

@emie 

There are a few ways to simulate an "out of memory issue" in a Linux environment. Here are a couple of methods:

  1. Using a memory hogging script: Create a basic script that consumes a large amount of memory. For example, you can use the following script to consume memory gradually: #!/bin/bash a=() while true; do a+=(0) done Run this script in the background. As the script continues to allocate memory, it will eventually consume all available memory, causing an "out of memory" error.
  2. Using a stress-testing tool: Install the stress tool on your Linux system (if not already installed). Run the stress command with the --vm option to stress the virtual memory subsystem. Specify the number of processes (--vm-bytes) and the amount of memory (--vm-keep) to consume. Example: stress --vm 1 --vm-bytes 1G --vm-keep This command will spawn a process that consumes 1GB of memory and keeps it allocated. You can adjust the parameters as per your requirements, increasing the memory consumption until the system runs out of memory.


Note: Be cautious while simulating an out of memory issue, as it can cause system instability and affect other running processes. Always perform such simulations on non-production systems or with appropriate precautions.

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by cecelia , 15 days ago

@emie 

As always, please use caution when simulating an out of memory issue on a system, as it can lead to system instability and potentially result in data loss. It is recommended to perform such simulations on a non-production system or in a controlled environment.


Here are a few more methods to simulate an "out of memory issue" on a Linux system:

  1. Using Fork Bomb: A fork bomb is a denial-of-service attack that consumes all available system resources. You can simulate this by executing the following command:
1
:(){ :|: & }; :


This command will create a function called ":" that recursively spawns itself in the background, consuming all available system resources.

  1. Using dd: The dd command can be used to create a large file that fills up the available disk space, causing memory issues indirectly. For example, you can run:
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dd if=/dev/zero of=/tmp/fillup bs=1M count=10000


This command will create a 10GB file (bs=1M count=10000) by filling it with zeros from /dev/zero. This operation can consume a significant amount of memory and disk space.

  1. Using memory-demanding applications: Running memory-intensive applications, multiple instances concurrently, or creating large datasets in memory can also lead to an out-of-memory situation. For instance, you could run multiple instances of a memory-intensive program to utilize available memory.


Remember to monitor your system's performance during these simulations and be prepared to kill the processes consuming excessive resources if needed. After simulating an out-of-memory condition, you may have to reboot the system to restore normal functionality.