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KB ID: 5928

Using multiple TeraStation iSCSI targets into one VMware ESXi datastore

Last Updated: 09/08/2025

Using multiple TeraStation iSCSI targets into one VMware ESXi datastore can be done by adding new storage devices to the datastore using “Add an Extent”. The datastore can span over multiple storage devices, yet appear as a single volume.

For detailed information and limitations of “Add an Extent”, please refer to the following VMware KBs.
Increase Capacity of vSphere VMFS Datastore
Increasing VMFS Datastore Capacity
 

Prerequisites 
1.    Refer to this KB to create iSCSI targets on the TeraStations
2.    Refer to this KB to connect the iSCSI targets to VMware ESXi but don’t create a new VMFS datastore just yet.
 

Demonstration environment in this article: 
ESXi 7.0 Update 3
TeraStation TS71210R Firmware Version: 1.34
TeraStation TS51220R Firmware Version: 2.10
 

1.    Access ESXi Host Client.
2.    Select "Storage" from left menu. Click "Devices"  tab.
Make sure the connected TeraStation iSCSI targets are listed.

3.    Create initial datastore:
•Click the “Datastores” tab.
•Click "New datastore"

•    Select "Create new VMFS datastore"

•    Give it a name
•    Select first iSCSI disk

•    Choose VMFS 6
•    Use maximum capacity

•    Click "Finish"

4.    Add second iSCSI target as extent:
•    Select the new datastore just created
•    Click "Actions" menu
•    Choose "Increase capacity"

•    Select "Add an extent to existing VMFS datastore"

•    Choose second iSCSI disk

•    Choose VMFS 6

•    Review and click Finish

•    After datastore is successfully extended, the capacity of the datastore will be the combination of two iSCSI targets. 

For detailed information and limitations of “Add an Extent”, please refer to the following VMware KBs.
Increase Capacity of vSphere VMFS Datastore
Increasing VMFS Datastore Capacity