For converting thick to thin using SvMotion, the destination datastore selected should be a different one than the source. Just changing the provisioning type will not work. Let us know if this is how you are doing it.
I am using a different destination datastore. It's only the disks attached to the paravirtual adapter that are failing.
what error do you get?
I don't get any errors, which is quite frustrating. It just doesn't work.
Did you already tried via PowerCLI?
Use Move-VM cmdlet with the -DiskStorageFormat parameter.
Example: Get-VM -Datastore <Datastorename> | Move-VM -Datastore <Datastorename> -DiskStorageFormat thin
makes no difference.
PS C:\Users> get-vm -name relimageatl01 | move-vm -Datastore at1_relativity_03 -DiskStorageFormat Thin
Name PowerState Num CPUs MemoryGB
---- ---------- -------- --------
RELIMAGEATL01 PoweredOn 8 16.000
Description Type Date Time Task Target User
"Migration from host at1esx21.kilpatrickstockton.ks, at1_relativity_02 completed" Information 10/12/2018 8:55:12 AM RELIMAGEATL01
As you can see, no errors. It just silently fails. As I've mentioned, this failure happens ONLY for disks attached to the paravirtual SCSI adapter. I can thick to thin & vice-versa all day long for disks attached to the other types of SCSI controllers.
Since it seems to be a bug, I have opened a case with VMware and will follow up here in case anyone encounters it.