Move / Delete esxi 5.5 vmkdump folder / files in datastore

When you upgrade to ESXi 5.5,the vmkdump folder may appear in some datastore.
Though this folder was Locked after ESXi host booting,you can still unlock it using ssh command.
Check .dumpfile:

ssh cmd

esxcli system coredump file get

Deactivate(unlock) .dumpfile:

ssh cmd

esxcli system coredump file remove --force

Now you can move vmkdump folder.
If the vmkdump folder (with .dumpfile) was moved to other datastore,you could reactivate it.
Reactivate .dumpfile:

ssh cmd

esxcli system coredump file set --smart --enable true