We need to extract some performance counters from VMware at the VM level related to the datastore. After extensive searching, we managed to do this natively using the key vmware.vm.discovery[url]. This includes the macros

{#DATASTORE.NAME} 

and 

{#DATASTORE.UUID} 

, which are sufficient for creating the appropriate performance counters. We extract them in the appropriate LLD rule, filtering them per VM, and use them to create performance counters related to the datastore. Everything works as it should.

The problem arises when a VM has disks allocated in different datastores, e.g., disk1 - DS1, disk2 - DS2. This rule detects only DS1 (the first occurrence), and the rest are omitted. It seems that the LLD rule needs to be modified so that the datastores are treated as an array of all DSs on the VM (similar to how it is handled for network interfaces).