ESXi 6.7 update 2 released in May 2019 adds VMFS6 to the list of supported file systems by the vSphere On-disk Metadata Analyzer (VOMA) to allow you to check and fix issues with VMFS volumes metadata, LVM metadata, and partition table inconsistencies.
This means you can save a lot of resources, time and money while troubleshooting corruption on VMFS6 datastore without the need to dump your metadata and request support to fix it. Going over this scenario without VOMA will kill days of work if you have multiple datastores affected and in some cases you could end up needing to restore from backups.
Before getting into this adventure without really knowing the results it is very important you have backups for all the machines or the volume. You can clone the volume to work with VOMA in the clone without needing to take the production volume offline. This will rely on the storage features.
Before VOMA version 0.8
Before this update if you experienced any metadata error or corruption in a VMFS6 datastore you needed to collect (dump) the datastore metadata and upload the dump file to a created VMware support case and get the updated dump to be imported back into your datastore for any chance to recover your machines from these errors.
VMware support analyze the uploaded file and runs a script to repair the errors (if can be repaired) then will assist to re-apply the metadata to your volume.
Steps for this procedure detailed on this old article before VOMA release in ESXi 5.5 https://kb.vmware.com/s/article/1020645
This same procedure is used if you run VMFS6 on ESXI version lower than 6.7u2
After VOMA version 0.8
To check your VMFS6 datastore using VOMA use this command
voma -m vmfs -f check -d /vmfs/devices/disks/naa.xxxxxx:1
voma -m vmfs -f check -d /vmfs/devices/disks/naa.xxxxxx
To fix detected errors, power off all vms in the volume, unregister all vms from inventory, unmount the datastore from all hosts and VOMA with -f fix option
voma -m vmfs -f fix -d /vmfs/devices/disks/naa.xxxxxx:1
voma -m vmfs -f fix -d /vmfs/devices/disks/naa.xxxxxx
In this case :1 is the partition for vmfs6. You can get a vmfs report with
You will see these type of messages. Each phase will show existing errors if present
Running VMFS Checker version 2.1 in check mode
Initializing LVM metadata, Basic Checks will be done
Checking for filesystem activity
Performing filesystem liveness check..|Scanning for VMFS-6 host activity
Phase 1: Checking VMFS header and resource files
Detected VMFS-6 file system
Phase 2: Checking VMFS heartbeat region
Phase 3: Checking all file descriptors.
Phase 4: Checking pathname and connectivity.
Phase 5: Checking resource reference counts.
Steps for this procedure detailed on this article on how to use VOMA