Troubleshooting Erratic vCenter Behavior Caused by Storage Issues

Products

• VMware vCenter Server

Issue/Introduction

This article addresses situations where vCenter Server exhibits unstable behavior, such as authentication errors, intermittent connection issues, or frequent restarts. These symptoms may be caused by underlying storage problems, particularly issues with the LUN hosting the vCenter Server VM.

Environment

- VMware vSphere 7.0 and newer
- vCenter Server
- ESXi hosts
- External storage arrays

Cause

Erratic vCenter behavior can sometimes be traced to storage issues, particularly problems with the LUN hosting the vCenter Server VM. Common indicators include high numbers of data write miscompares, frequent I/O errors, or other storage-related issues visible in ESXi host logs.

Resolution

1. Identify the LUN hosting the vCenter Server VM:
   a. Log into the ESXi host that runs the vCenter Server VM using SSH or the Direct Console User Interface (DCUI).
   b. Use the following command to list all VMs and their datastores:
      ```
      vim-cmd vmsvc/getallvms
      ```
   c. Identify the datastore where the vCenter Server VM is located.
   d. Use the following command to match the VMFS UUID with the NAA ID:
      ```
      esxcli storage vmfs extent list
      ```
   e. Note the NAA ID of the LUN hosting the vCenter Server VM.

2. Examine the ESXi host logs for storage-related issues:
   a. Check the following log files for errors related to the identified LUN:
      ```
      /var/log/vobd.log
      /var/log/vmkernel.log
      ```
   b. Look for repeated error codes, such as "0xe 0x1d 0x0". Hundreds or thousands of these indicate severe storage issues.
   c. Search for ongoing I/O errors related to the LUN.

3. If severe storage issues are detected:
   a. Contact your storage array vendor to investigate and resolve the underlying storage problems.
   b. Consider opening a case with VMware Support for further analysis and guidance on interpreting error codes and log entries.

4. After addressing storage issues, assess vCenter Server health:
   a. Check vCenter Server logs for signs of corruption or data inconsistency.
   b. Look for erratic or inconsistent behaviors, such as:
      - Having to retry the same credentials repeatedly to log in
      - Needing to frequently reboot vCenter to get it to respond
      - Intermittent connection issues between vCenter and ESXi hosts
      - Unexpected service failures or restarts
   c. If these issues persist, consider rebuilding the vCenter Server from scratch.

Additional Information

VMware ESXi SCSI Sense Code Decoder