LUN visibility issues preventing datastore creation on ESXi
Article ID: 438689
Updated On:
Products
Issue/Introduction
This article outlines troubleshooting steps for situations where ESXi hosts cannot see LUNs that have been presented to them.
Symptoms:
- The ESXi host can successfully see the storage array targets, but one or more specific LUNs are not visible.
- The ESXi host is unable to detect the presented LUNs.
Environment
VMware vSphere ESXi 8.x
VMware vSphere ESXi 7.x
Cause
By design, VMware ESXi hosts do not automatically display newly provisioned LUNs upon presentation. Continuous storage scanning is omitted by default to minimize performance overhead on the underlying storage network fabric. Administrators must execute a manual or scheduled storage rescan to update the Host Bus Adapters (HBAs) and prompt the host to discover new storage devices.
Resolution
To restore visibility to the LUNs, perform the following steps:
- Run a storage rescan to restores visibility of the LUN(s) to ESXi hosts. For more information, see Performing a rescan of the storage on an ESXi host
- Confirm that the ESXi hosts can successfully detect the newly presented LUNs. For more information, see Obtaining LUN pathing information for ESXi hosts.
Note: Perform a rescan of storage devices. A rescan of storage devices is needed when a storage device has been added, removed, expanded or changed from the array. for reference
Performing a rescan of the storage on an ESXi host - Once the LUNs are visible, create Datastore, For instructions see: Create a vSphere VMFS Datastore.
Additional Information
For Reference, If LUNs are not visible on the ESXi host, see:
- For fiber channel LUNs: Troubleshooting fibre channel storage connectivity
- For iSCSI LUNs: Troubleshooting ESXi connectivity to iSCSI arrays using software initiators
To add additional LUNs to the newly created datastore, you will need to add an extent. Refer to the article: Increase or expand the datastore directly from the ESXi host
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