VM VMDK files change from thin to thick provisioning suddenly

[Ewing1]

VM VMDK files change from thin to thick provisioning suddenly which cause datastore almost full

Ref ls -al command show provisioning sizing and du -sk command show real sizing usage

[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] du -sk VM_NAME001.mus-hk.com*flat.vmdk
98842624 VM_NAME001.mus-hk.com-flat.vmdk <== same as thick provisioning sizing 
2140343296 VM_NAME001.mus-hk.com_2-flat.vmdk <== same as thick provisioning sizing
2030645248 VM_NAME001.mus-hk.com_3-flat.vmdk <== same as thick provisioning sizing
2129701888 VM_NAME001.mus-hk.com_4-flat.vmdk <== same as thick provisioning sizing
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com]

[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] ls -al VM_NAME001.mus-hk.com*flat.vmdk
-rw------- 1 root root 107374182400 May 26 03:56 VM_NAME001.mus-hk.com-flat.vmdk
-rw------- 1 root root 2199023255552 May 26 03:11 VM_NAME001.mus-hk.com_2-flat.vmdk
-rw------- 1 root root 2199023255552 May 26 03:51 VM_NAME001.mus-hk.com_3-flat.vmdk
-rw------- 1 root root 2199023255552 May 26 03:56 VM_NAME001.mus-hk.com_4-flat.vmdk
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com]

[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com.vmdk ddb.thinProvisioned = "1" <== it show VMware config as thin provisioning
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com_2.vmdk ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com_3.vmdk ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com_4.vmdk ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com]

After one week, I aware this VM change back to original thin provisioning suddenly. We don’t have any change.
It is critical issue. We don’t accept the VMware VM configuration suddenly change.

>>

[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] du -sk VM_NAME001.mus-hk.com*flat.vmdk
49970176 VM_NAME001.mus-hk.com-flat.vmdk
1140914176 VM_NAME001.mus-hk.com_2-flat.vmdk <== 1140G
388904960 VM_NAME001.mus-hk.com_3-flat.vmdk <== 388G
641392640 VM_NAME001.mus-hk.com_4-flat.vmdk <== 641G
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VMi_NAME001.mus-hk.com] ls -al VM_NAME001.mus-hk.com*flat.vmdk
-rw------- 1 root root 107374182400 May 30 08:19 VM_NAME001.mus-hk.com-flat.vmdk
-rw------- 1 root root 2199023255552 May 30 08:05 VM_NAME001.mus-hk.com_2-flat.vmdk
-rw------- 1 root root 2199023255552 May 30 08:00 VM_NAME001.mus-hk.com_3-flat.vmdk
-rw------- 1 root root 2199023255552 May 30 08:18 VM_NAME001.mus-hk.com_4-flat.vmdk
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com.vmdk
ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com_2.vmdk
ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com_3.vmdk
ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com] grep ddb.thinProvisioned VM_NAME001.mus-hk.com_4.vmdk
ddb.thinProvisioned = "1"
[root@ESXi_NAME003:/vmfs/volumes/604ebfe2-c3f1e74f-b1c4-1402ec6cdce0/VM_NAME001.mus-hk.com]