FATAL ERROR: 28 (CRC error) - ESXi Host not Booting

Products

• VMware vSphere ESXi

Issue/Introduction

ESXi host fails while booting up with Fatal Error: 28 (CRC error). 

 CRC error during decompression.
Error: 28 (CRC error) while loading module: /vmx.v00
Fatal error: 28 (CRC error)

As seen from host DCUI screenshot:

Environment

VMware vSphere ESXi

Cause

The CRC error during decompression while booting VMware ESXi typically results from data corruption due to:

• Bad bootable media (like a faulty SD card, USB memory stick, failing SSD or incorrectly burned DVD).
• Network issues during the ISO download, leading to incomplete or corrupt files.

Resolution

Steps to resolve hardware-related CRC Errors:

• Diagnose the storage boot device health
  • Use tools available with your Hardware Vendor to test the storage device for read/write errors and bad sectors.
  • If using an SD card as the boot device for ESXi, it may have bad sectors or be nearing the end of its life. SD cards, especially those used in high-usage environments, can degrade over time and develop faulty blocks that cause data corruption. 
    • If the tool reports issues, the SD card is likely faulty and should be replaced.
• Replace the storage boot device
  • If the diagnostic tests confirm that the storage boot device has developed bad sectors or is corrupted, replacing the storage device is the best course of action.
  • Recommended Steps:
    • Use a high-quality SSD, SD card or USB drive designed for enterprise use if possible. For example, SLC (Single-Level Cell) flash memory cards are more reliable than standard consumer-grade SD cards, which typically use MLC (Multi-Level Cell) or TLC (Triple-Level Cell) memory, known to wear out faster.
    • Avoid reusing the faulty SD card, as even after formatting, it may still have bad sectors.
• After replacing the faulty storage, reinstall ESXi on the host.

Additional Information

Workaround:

In some cases, the ESXi host can be reverted to the previous installation of ESXi on the secondary bootbank during the boot process. See:

Reverting to a previous version of ESXi 6.x, 7.x or 8.x