By installing the memtester package, you can check your system for errors while it's still running. No need for a restart, just run that application.
To install it, open a terminal and type:
sudo apt install memtester
You can then use it like so:
sudo memtester 1024 5
This should allocate 1024MB of memory, and repeat the test 5 times.
Update
- If you have more RAM like 4GB or 8GB, it is up to you how much memory you want to allocate for testing.
- As your operating system, current running process might take some amount of RAM, Please check available free RAM and assign that too memtester.
- If you are using a 32 Bit System, you can't test more than 4 GB even though you have more RAM (32 bit systems doesn't support more than 3.5 GB RAM).
- If your system is very busy and you still assigned higher than available amount of RAM, then the test might get your system into a deadlock, and leads to system to halt, be aware of this.
- Run the memtester as root user, so that memtester process can malloc the memory, once its gets hold on that memory it will try to apply lock. if specified memory is not available, it will try to reduce required RAM automatically and try to lock it with mlock.
- If you run it as a regular user, it can't auto reduce the required amount of RAM, so it can't lock it, it tries to get hold on that specified memory and starts exhausting all system resources.