After taking the console facing error: "A disk read error occurred".

Products

• VMware vSphere ESX 7.x
• VMware vSphere ESX 8.x

Issue/Introduction

While booting it display : "A disk read error occurred. Press Ctrl+Alt+Del to restart."

Environment

VMware vSphere ESXi 7.0

VMware vSphere ESXi 8.0

Cause

This error message indicates that the disk structure is corrupted and unreadable. If you're using a Generation 1 VM, it's also possible that the disk partition containing the boot configuration data isn't set to Active.

Resolution

• Set Partition Status to Active
• Fix the Disk Partition

1. Open Computer management > Disk management. Make sure that the disk is flagged as Online in the Disk Management console. Note the drive letter that is assigned to the attached system disk.

   

2. Identify the Boot partition and Windows partition. If there's only one partition on the OS disk, this partition is both Boot partition and Windows partition.

   If the OS disk contains more than one partition, you can identify the partitions by viewing the folders in them:

   • The Windows partition contains a folder that is named Windows, and this partition is larger than the others.

   • The Boot partition contains a folder that is named Boot. This folder is hidden by default. To see the folder, you must display the hidden files and folders and disable the Hide protected operating system files (Recommended) option. The boot partition is typically 300 MB~500 MB.

3. Run the following command as an administrator to create a boot record:

   ConsoleCopy

    

   bcdboot <Windows partition>:\Windows /S <windows partition>: 
   

4. Use the DISKPART tool to check whether the Windows partition is active:

   1. Open an elevated command prompt and open the DISKPART tool.

      diskpart

   2. List the disks on the system and look for added disks and proceed to select the new disk. In this example, the new disk is Disk 1.

      psCopy

       

      list disk
      sel disk 1
      

      

   3. List all the partitions on that disk and then proceed to select the partition you want to check. Usually System Managed partitions are smaller and around 350 MB in size. In the following image, this partition is Partition 1.

      psCopy

       

      list partition
      sel partition 1
      

      

      1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. Check the status of the partition. In our example, Partition 1 is not active.

                                                   detail partition

                                                   

                                                   If the partition isn't active, change the Active flag and then recheck the change was done properly.

                                                   psCopy

                                                    

                                                   active
                                                   detail partition
                                                   

                                                   

   4. Exit the DISKPART tool.

      exit

 

1. Open command prompt (cmd.exe).

2. Use the following command to run CHKDSK on the disk(s) and perform error fixes:

   chkdsk <DRIVE LETTER>: /f

   Adding the /f command option fixes any errors on the disk. Make sure to replace < DRIVE LETTER > with the letter of the attached OS disk.

 

If you have a recent backup of the VM, you may try restoring the VM from the backup to fix the boot problem.

If not worked then need to rebuild the OS.

For more detail, Please connect with Guest OS vendor to troubleshoot and resolve the issue.