So, here is a strange one. I have a vm (Windows 2016) that had issues with the OS disk and needed to be rebuilt from scratch. On this vm there were several vmdk files attached from a few different datastores. I powered down the vm, recreated new OS disk, reinstalled windows then re-attached other vmdk files. One of the vmdk disk contents are fine, readable, can copy them, etc. Other vmdk disks (one of which is on same datastore as working vmdk) are showing files as 0 bytes and they are unreadable, cannot copy them, etc.
I have run chkdsk /f in windows, nothing. I ran vmkfstools --fix check on vmdk files themselves, no disk errors.
Any ideas!?
In case anyone can benefit from this, issue was with moving drives from one 2016 server to another and not having deduplication service running. Took awhile to find that out, glad I did.