Known Issue: initrd.img.xz Not Found

This is a problem that is fixed in CSM 1.0 and later, but if your system was upgraded from CSM 0.9 you may run into this. Below is the full error seen when attempting to boot:

Loading Linux  ...
Loading initial ramdisk ...
error: file `/boot/grub2/../initrd.img.xz' not found.
Press any key to continue...
[    2.528752] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[    2.537264] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.3.18-24.64-default #1 SLE15-SP2
[    2.545499] Hardware name: Cray Inc. R272-Z30-00/MZ32-AR0-00, BIOS C27 05/12/2021
[    2.553196] Call Trace:
[    2.555716]  dump_stack+0x66/0x8b
[    2.559127]  panic+0xfe/0x2d7
[    2.562184]  mount_block_root+0x27d/0x2e1
[    2.566306]  ? set_debug_rodata+0x11/0x11
[    2.570431]  prepare_namespace+0x130/0x166
[    2.574645]  kernel_init_freeable+0x23f/0x26b
[    2.579125]  ? rest_init+0xb0/0xb0
[    2.582623]  kernel_init+0xa/0x110
[    2.586127]  ret_from_fork+0x22/0x40
[    2.590747] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[    2.690969] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---

Fix

Follow these steps on any NCN to fix the issue:

  1. Install the Shasta 1.4 (a.k.a. CSM 0.9) csm-install-workarounds RPM. See the CSM 0.9 documentation for details on how to do this.

  2. Run the CASMINST-2689.sh script from the CASMINST-2689 workaround at the livecd-post-reboot breakpoint:

    ncn# /opt/cray/csm/workarounds/livecd-post-reboot/CASMINST-2689/CASMINST-2689.sh

  3. Run these commands:

    ncn# for i in $(grep -oP 'ncn-\w\d+' /etc/hosts | sort -u |  tr -t '\n' ' '); do
         scp -r /opt/cray/csm/workarounds/livecd-post-reboot/CASMINST-2689 \
              $i:/opt/cray/csm/workarounds/livecd-post-reboot/
      done
ncn# pdsh -b -S -w $(grep -oP 'ncn-\w\d+' /etc/hosts | sort -u |  tr -t '\n' ',') \
      '/opt/cray/csm/workarounds/livecd-post-reboot/CASMINST-2689/CASMINST-2689.sh'

  4. Remove the Shasta 1.4 install workaround RPM from the NCN.

    ncn# rpm -e csm-install-workarounds

Validate

Running the script again will produce this output:

Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.
Examining /metal/boot/boot/kernel...kernel is OK.
Examining /metal/boot/boot/initrd.img.xz...initrd.img.xz is OK.