Datastores and devices are not visible on certain ESXi hosts

Products

• VMware vSphere ESXi

Issue/Introduction

When attempting to view datastore information via the host GUI or command line, one or more hosts with uniform storage configurations, are unable to view specific LUNs and datastores while other ESXi hosts are able to browse the LUNs and datastores missing from the other hosts.

Environment

VMware vSphere ESXi

Cause

The hosts have become disconnected from the datastore and are unable to regain a valid connection.

Resolution

1. Attempt a storage rescan to accurately reflect modifications on the ESXi hosts when a storage device has been added, removed, or altered within the array. The following KB provides steps on how to perform rescan of the storage on an ESXi host:
   Performing a rescan of the storage on an ESXi host
2. If the storage device still can't be found after rescanning, and the user has checked that the storage array configuration for that device is correct, then a reboot of the ESXi hosts that aren't showing the LUN/datastore may be required.
   There are several reasons why an ESXi reboot might cause a previously invisible datastore to become visible:
   
   • Rescan and Discovery: During the boot process, ESXi performs a scan and discovery of storage devices and LUNs (Logical Unit Numbers). This process can sometimes detect datastores that were not properly recognized or available before the reboot.
   • Storage Controller Initialization: The reboot process allows the storage controllers to properly initialize and establish connections with the storage arrays. This can make previously unavailable datastores accessible to the ESXi host.
   • Driver Loading: Sometimes, the necessary drivers for the storage controller or the storage array might not have been loaded correctly before the reboot. The reboot process ensures that all the required drivers are loaded, enabling the ESXi host to recognize and access the datastore.
   • Configuration Changes: If any configuration changes were made to the storage array or the ESXi host (such as adding new LUNs or modifying permissions), a reboot is often required for these changes to take effect and for the ESXi host to recognize the updated storage landscape.
3. If rebooting the host or performing a storage rescan does not resolve the issue, open a support case with both the storage array vendor and the Broadcom Storage team for further investigation and root cause analysis. Creating and managing Broadcom cases