Dropping Into "initramfs" Prompt After Installing Ubuntu 22.04 LTS on to Dell VRTX Server

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Background

During one of the recent projects, I want to install a Linux OS onto a Dell VRTX server. Without checking the hardware compatibility list and with limited knowledge about the Dell VRTX server platform, I started to install Ubuntu 20.04 LTS on one of the server blades in the chassis. And running into some interesting issues, which forces me to learn more about the Dell VRTX platform and Linux OS. Though spending quite a lot of effort in sorting out the issue, I am happy to share it with others who are interested to know more about it.

Server blades inside the Dell VRTX chassis have no hard hard drive installed. But the chassis enclosure has 25 2.5 in SAS hard drive installed. Before starting the whole process, I picked up two of the SAS hard drive and created a RAID-1 logical drive, and assigned it to the server blade. I thought the system would be able to boot from the new logical drive.

The Start of the Problem

After inserting the USB disk with Ubuntu 22.04, the server blade was able to boot from it and completed the installation process. During the process, the installer identified two storage SCSI disk storage devices. Besides the logical drive created beforehand, there is another IDSDM device. As I am not sure what that device is, I just ignored it.

The installation progress was smooth. After it completed all its tasks, I selected the reboot button to reboot the OS.

After the system completed its POST process, surprisingly, it booted into the VMware ESXi environment.  

Since there is no meaningful data on the new logical drive I created for the OS, the only possibility is that there is ESXi installed on the IDSDM storage device.

The IDSDM Storage Device

After some research, it turned out the IDSDM stands for Dell's Internal Dual SD Module.

The Internal Dual SD Module is a redundant SD-card module for embedded hypervisors. With the ESXi the system was booting into, it makes all sense now.
I tried to boot into the BIOS setup utility, but the logical drive is not listed as a bootable drive. Then, I suddenly realized the SCSI card the system is using does not have an option ROM to allow the system to boot from the logical drive.

Failed to Activate Root Filesystem

How about formatting the IDSDM device and installing/boot and /boot/efi into that drive? So I restarted the installation process. As expected, the installation process was smooth.
However, after a reboot, the system failed to boot successfully and dropped into the shell with the (initramfs) prompt. 

... 

mdadm: No arrays found in config file or automatically 

mdadm: No arrays found in config file or automatically 

mdadm: No arrays found in config file or automatically 

done. 

Give up wating for root file system device.  Common problems: 

 - Boot args (cat /proc/cmdline) 

   - Check rootdelay= (did the system wait long enough?) 

 - Missing modules (cat /proc/modules; ls /dev) 

ALERT!  /dev/mapper/vg0-root does not exist.  Dropping to a shell! 

 

 

BusyBox v1.30.1 (Ubuntu 1:1.30.1-7ubuntu3) built-in shell (ash) 

Enter 'help' for a list of built-in commands. 

 

(initramfs) 

(initramfs) grep multi /proc/modules 

multipath 20480 0 - Live 0xffffffffc0345000 

(initramfs) multipath 

sh: multipath: not found 

(initramfs) lvm 

Cannot read termcap database; 

using dumb terminal settings. 

lvm> pvs 

  WARNING: Not using device /dev/sdb for PV VQjr3U-LVUS-VPIa-FhL7-KAOx-kIe1-vhozu7 

  WARNING: PV VQjr3U-LVUS-VPIa-FhL7-KAOx-kIe1-vhozu7 perfers device /dev/sda/ because device was seen first 

  PV VG Fmt Attr PSize PFree 

  /dev/sda vg0 lvm2 a-- 1.09t 0 


How come both sda and sdb has the same identifier?  Because of that, the system refused to activate the LVM logical volume, which was created during the installation process. Because the root filesystem was created inside one of the logical volumes, now the system cannot mount the root filesystem. As a result, it stopped the boot process and dropped into the shell environment.
Why did the system find the same logical drive both as sdb and sdc?
While I was putting the article together, I had already figured out what happened. I will explain more about the Dell VRTX system and the issue in the next post. Stay tuned. :)

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