Appendix: Creating Diagnostic Test Images¶
In uncommon situations a cluster administrator may wish to execute a self-contained diagnostic program as a compute node image. "Self-contained" means the diagnostic program itself functions as a kernel and does not need an initrd.
An example is the
memtest86+ memory diagnostic,
which can be downloaded from www.memtest.org:
# Download the latest compressed Linux 64-bit ISO: mt86plus_6.01_64.iso.zip # Uncompress the downloaded file to expose the ISO: unzip mt86plus_6.01_64.iso.zip # Mount the ISO sudo mkdir -p /mnt/mt86plus_6.01_64 sudo mount mt86plus_6.01_64.iso /mnt/mt86plus_6.01_64 -o loop # Create a new boot configuration that consists of just the efi binary: scyld-bootctl create name=Memtest_6.01_Boot kernel=@/mnt/mt86plus_6.01_64/EFI/BOOT/bootx64.efi # Configure the desired node (e.g., n123) to execute that new boot configuration: scyld-nodectl -i n123 set _boot_config=Memtest_6.01_Boot # Ensure that you have a method to view serial output from that node. # For example, if serial output for node n123 uses ttyS1: scyld-bootctl -i Memtest_6.01_Boot update cmdline="console=ttyS1,115200" # And then reboot that node. scyld-nodectl -i n123 reboot
memtest86+ version 6.01 works for both legacy and uefi PXE booting.