Changing an ATS-only volume to public in ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides steps to change an ATS-only volume to be accessible using SCSI. It must be unmounted and remounted to apply the change and initialize the new locking mechanism.

Environment

• VMware vSphere ESXi 6.0
• VMware vSphere ESXi 5.5
• VMware vSphere ESXi 6.5

Resolution

To change an ATS-only volume to public (SCSI+ATS):

1. Migrate all virtual machines and templates off the datastore using Storage vMotion. There should be nothing registered to the datastore.
   
   
2. Unmount the datastore from all ESXi hosts. For more information, see Unmounting a LUN or detaching a datastore/storage device from multiple VMware ESXi 5.x/6.0 hosts (2004605).
   
   
3. Run this command to allow non ATS access to the volume:
   
   # vmkfstools --configATSOnly 0 /vmfs/devices/disks/naa.####:1
   
   
4. Remount the datastore to the ESXi hosts.
   
   
5. Migrate or re-register the virtual machines back to the original datastore.
   
   
6. After completing these steps for each target datastore and all datastores you want to have public access are configured correctly. Run the relevant esxcli system settings advanced command(s) to apply a global configuration to the ESXi host.

Notes:

• If you cannot migrate virtual machines off the datastore using Storage vMotion, you can unregister virtual machines temporarily to allow the unmount and remount.
  
  Caution: This clears statistical data for the virtual machine in vCenter Server. Virtual machine configuration data, including solutions/plug-in configuration data (backup jobs/schedules, replication/protection mappings, etc) may also be lost if the virtual machine it relates to is removed from the vCenter Server inventory.
  
  
• If there are VMware View linked clones residing on the datastore, they cannot be migrated using Storage vMotion. The linked clones must be decommissioned and recreated, or unregistered and re-registered. Ensure you make suitable changes in View Manager to prepare for the datastore maintenance.

Additional Information

How to unmount a LUN or detach a datastore device from ESXi hosts