VM stops suddenly when vFAT partitions exists on the RDM of the VM.

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• VM stops suddenly during VM reconfiguration
• Power On fails with similar errors in vmware.log

         Log location: /vmfs/volumes/datastorename-ID/vmname/vmware.log

YYYY-MM-DDT00:00:30.207Z| vmx| I125: AIOGNRC: Failed to open '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' : Failed to lock the file (40003) (0x2003).
YYYY-MM-DDT00:00:30.207Z| vmx| I125: AIOMGR: AIOMgr_OpenWithRetry: Descriptor file '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' locked (try 1)
YYYY-MM-DDT00:00:30.509Z| vmx| I125: AIOGNRC: Failed to open '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' : Failed to lock the file (40003) (0x2003).
YYYY-MM-DDT00:00:30.509Z| vmx| I125: AIOMGR: AIOMgr_OpenWithRetry: Descriptor file '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' locked (try 2)
YYYY-MM-DDT00:00:30.811Z| vmx| I125: AIOGNRC: Failed to open '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' : Failed to lock the file (40003) (0x2003).
YYYY-MM-DDT00:00:30.811Z| vmx| I125: AIOMGR: AIOMgr_OpenWithRetry: Descriptor file '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' locked (try 3)
YYYY-MM-DDT00:00:31.114Z| vmx| I125: AIOGNRC: Failed to open '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' : Failed to lock the file (40003) (0x2003).
YYYY-MM-DDT00:00:31.114Z| vmx| I125: AIOMGR: AIOMgr_OpenWithRetry: Descriptor file '/vmfs/volumes/####-#####-####-####/rdm-test1/rdm-test1-rdmp.vmdk' locked (try 4)
 

Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

Environment

VMware vSphere ESXi 6.7

VMware vSphere ESXi 7.0

VMware vSphere ESXi 8.0

Cause

 ESX bootup requires identification of boot partitions, which are vFAT as per design
 The VM is configured with a Raw Device Mapping (RDM) to a system disk
 User might have created a vFAT partition for scratch purpose within the RDM luns which would result in ESXi mounting them
 Eventually the VM will fail to power on because the RDM with a vFAT partition fails to open.

Resolution

vFat partition on RDM is unsupported as per design by VMware
This is an expected behavior if RDMs contain vFAT partitions