Hi Patrick,
Is it safe to do the online expand VMFS when the vm is running?
Yes no worries on that.
After expand the VMFS, I will expand the D:\ drive of that VM from 160GB to 300GB, that means the vmdk file will be 300G,
My question is that vmdk will growth to 300GB across the old size vmfs and the new size vmfs 300GB, any issue on this scenario?
ie can the vmdk able to expand it size and use on a expanded VMFS voluem?
After expand the VMFS, your host will only see a unique Datastore of 500GB. So you can expand your vmdk to 300GB without issue.
For expand your vmdk, just right-click on your vm --> "Edit Setting" --> Select your hard disk--> And type the new size. Then in your guest OS expand your partition.
Regards,
Julien.