Docker module diskio and external storage

We are are currently using metricbeat docker module to monitor basic metrics from our containers on one host machine, however we are protoyping scaling our system to work accross multiple machines, and we would like to be able to continue monitoring metrics.

We have moved a shared volume from the host machine to external storage and now we have no metrics for diskio on our graphs from metricbeat.

Does the drive that the container is writing to have to be on the same machine as the docker container to get diskio stats? How are the diskio stats per container derived? If we run metricbeat on the machine where the external storage is then we would not be able to get the stats per container so is there any way to still get these metrics?