Linux Administration Cookbook

Memory testing

Memory is a little easier to test, though the most thorough way of checking every inch of your DIMMs is to take the box offline for a few hours while you run Memtest86+.

Programs such as memtester also exist, which can be executed on a running system. The problem with these types of test is that they won't test memory already in use by the system, and they can end up fighting processes such as the Out Of Memory (OOM) killer.

If you have the ISO image from the Memtest86+ website, you can attach it to your VM and boot into the program (completely independently of CentOS).

It will look something like this:

Any errors will show ...