Memtest86+

Resources

memtest86+ is memory test software based on the (commercially available) memtest86 program.

Installation

USE flags

USE flags for sys-apps/memtest86+ Memory tester based on PCMemTest

`+boot`	Install to /boot in addition to /usr/share/memtest86+/
`bios32`	Compile a BIOS-bootable 32bit memtest image
`bios64`	Compile a BIOS-bootable 64bit memtest image
`iso32`	Compile a 32bit ISO image
`iso64`	Compile a 64bit ISO image
`secureboot`	Automatically sign efi executables using user specified key
`uefi32`	Compile a EFI32-bootable 32bit memtest image
`uefi64`	Compile a UEFI-bootable 64bit memtest image

Data provided by the Gentoo Package Database · Last update: 2025-04-10 10:17 More information about USE flags

Prerequisites

Memtest86+ does not support UEFI. You can switch to Memtest86 V5 or newer for UEFI supported memtesting.

Be sure /boot (where the GRUB files are typically installed) is available before installing memtest86+! If /boot is on a separate partition (which it WILL BE if the partitioning scheme in the Gentoo handbook was used for this Gentoo install), then be sure the mount command is run before the emerge section below:

root #mount /boot

If no errors are return then boot should be successfully mounted. Check by running the mount command without any arguments and parsing the output with grep:

user $mount | grep boot

boot

Emerge

Ask Portage to install it:

root #emerge --ask sys-apps/memtest86+

Configuration

GRUB legacy

Replace the ? (question marks) in the file below with correct numbers for the system's boot partition:

FILE /boot/grub/grub.conf

title=memtest86+
root (hd?,?)
kernel /boot/memtest86plus/memtest

GRUB2

For GRUB2 just run grub-mkconfig. As long as the package has been emerged, a configuration file has already been installed to /etc/grub.d/39_memtest86+:

root #grub-mkconfig -o /boot/grub/grub.cfg

Note
If GRUB2 was installed with the multislot USE flag, use the command grub2-mkconfig instead.

LILO

For LILO, add this to the lilo.conf configuration file:

FILE /etc/lilo.conf

image  = /boot/memtest86plus/memtest
label  = memtest86+

Then rebuild LILO's MBR entry:

root #lilo

Syslinux

Add this to the configuration file:

FILE /boot/extlinux/extlinux.conf

LABEL memtest86+
	MENU LABEL memtest86+
	LINUX /boot/memtest86plus/memtest

Usage

To use memtest86+ the system needs to be rebooted using the newly added boot item

Removal

Unmerge

root #emerge --ask --unmerge sys-apps/memtest86+

External resources

http://www.pcworld.com/article/232640/memtest86.html - A PCWorld article describing the usefulness and features of memtest86+.