Extending a VMFS volume to use new LUN space after expansion

Products

• VMware vSphere ESXi

Issue/Introduction

I expanded a SAN LUN that has a VMFS volume on it. How can I extend that volume to use the newly added LUN space?

Environment

VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Resolution

VMFS volumes do not automatically expand. You need to extend the volume manually by taking these steps:

1. Create a new VMFS partition on the free space.
2. Use the new partition as an extent candidate for the original volume.

Before performing this procedure, on a safer side you may:

• Have all virtual machines on this volume powered down.
• Have no active virtual swap files on this volume.
• Have no service console processes using the VMFS volume. In addition, if you are logged on to the service console, you must not cd to any directory used by the VMFS volume.
• Ensure that the LUN has not exceeded the maximum LUN size as described in the Configuration Maximums document for the applicable ESX/ESXi version.

Increasing the capacity of ESXi 7.x Datastores

See the following KBs:

• Extending or increasing a datastore through vCenter Server fails
• Unable to expand a VMFS 5/6 datastore for any volume of size that is greater than or equal to 16TB

For information on increasing the capacity of a datastore under ESXi 7.x, see the Increase VMFS Datastores section of the vSphere 7.x Storage Guide.

For information on increasing the capacity of the datastore via the ESXi 7.x command-line, see Using vmkfstools section of the VMware vSphere 7.x Storage Guide.