If you suspect an issue with your system RAM, you should try to use a tool, that will write data in 100% of your RAM and let you know the errors it could get. One such tool available for linux is ‘Memtest+’
How to install memtest+ in CentOS 7
To install memtest+, run the following command in yum:
yum install memtest86+
Now, this will install memtest+ for you. But memtest+ runs the memory test at boot time. To accomplish that, you need to install memtest+ in grub. Memtest+ comes with a command, that does it for you. Run the following to do this:
This would install the memtest for grub. But you would still need to remake the grub.cfg file for CentOS 7. To do that, run the following:
grub2-mkconfig -o /boot/grub2/grub.cfg
Now, reboot the server and select memtest from the boot screen. Memtest will automatically complete the process and let you know the result on that screen.