In the output "ds1" shows up as "VMFS-unknown version", which most likely means that the datastore has been created using a newer ESXi/VMFS version than what ESXi 6.0 supports.
This bringa us back to the recommendation for patching, or upgrading the host. In case this is a standalone host, which supports ESXi 6.5, or newer, I'd consider upgrading to the newest supported version/build. In case it's managed by vCenter Server, or requires support for any 4rd-party applications, aou'll check the compatibility before upgrading the host.
André