Unable to see extra space on a datastore contained on a LUN

Products

VMware vSphere ESXi

Issue/Introduction

This article provides the steps required to expand a LUN configured for replication, so that you can expand the datastore contained on the LUN.

You are unable to see additional space added to a VMFS datastore volume connected to an ESXi/ESX, you experience these symptoms:

The extra storage space you have assigned is not visible in the devices section of your host's storage configuration
A rescan of the ESXi host's connected storage does not resolve the issue. For instructions, see Performing a rescan of the storage on an ESX/ESXi host (1003988)
The LUN is being replicated using LUN replication software, such as EMC Recoverpoint

In some scenarios, the expansion task may fail with with error "vim.fault.HostConfigFault"

You may see below events in hostd.log

2024-09-19T17:48:04.913Z info hostd[2100531] [Originator@6876 sub=Solo.Vmomi opID=esxui-900c-a0e5 user=root] Throw vim.fault.HostConfigFault
2024-09-19T17:48:04.913Z info hostd[2100531] [Originator@6876 sub=Solo.Vmomi opID=esxui-900c-a0e5 user=root] Result:
--> (vim.fault.HostConfigFault) {
--> faultMessage = (vmodl.LocalizableMessage) [
--> (vmodl.LocalizableMessage) {
--> key = "com.vmware.vim.hostsvc.storage.updateDiskFailed",
--> arg = (vmodl.KeyAnyValue) [
--> (vmodl.KeyAnyValue) {
--> key = "disk",

Environment

VMware vSphere ESXi 6.x
VMware vSphere ESXi 5.x

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Cause

This issue is caused by the configured mirror relationship between the source and target LUN or the LUN being mounted as read-only to DR site with different LUN number and managed by the same vCenter server.

Resolution

Warning: This will require an intervention from the Storage array to resolve the issue.

To resolve the issue you will need to temporarily break the mirror relationship between the LUN containing the VMFS datastore and its replica. The storage vendor will likely need to be engaged to apply the required changes.

Ensure that a full and valid backup of all important files and virtual machines on the LUN/Datastore exists
Temporarily break the replication between source and target LUN. Contact your storage vendor for detailed information.
If replication is not configured and the LUN is mounted with different LUN number to another site in the same vCenter server, unmount the datastore and remove the mapping the storage array to the DR site and expand the volume on the primary site.
Expand both the source and target LUNs to the required size using the storage array management software
Re-establish the replication between the source and target LUNs, (resync them)
Expand the VMFS datastore as normal. For details, see Growing or expanding a VMFS volume or datastore (1017662)

Additional Information

Performing a rescan of the storage on an ESX/ESXi hot

Unable to grow or expand a VMFS volume or datastore