Cannot mount the VMFS5 datastore when using storage encryption appliances

Products

• VMware vSphere ESXi

Issue/Introduction

• After adding a storage encryption appliance to the SAN, that VMFS5 datastore cannot be mounted.
• You are unable to mount the datastore manually.
• The VMFS5 datastore was newly created on a storage array that supports VAAI ATS Primitive (Hardware Accelerated Locking).

Environment

VMware vSphere ESXi 5.0

Resolution

Some storage encryption appliances may block certain SCSI commands, including ATS commands, sent from ESXi hosts. VMFS5 datastores newly created on ATS-capable devices are marked as ATSOnly after the first successful ATS command to the device. This allows all hosts sharing the datastore to utilize ATS without checking whether or not the storage array supports it. When the storage encryption device is then added to the SAN, it blocks the ATS commands. As a result, the host assumes that the array does not support ATS because it did not receive the expected response. The expected behavior is that the host does not fall back to using SCSI-2 Reservations for locking mechanism on the ATSOnly VMFS5 datastore, which then gets unmounted and cannot be mounted again.

To work around this issue, disable ATSOnly on the VMFS5 datastore.

Note: All virtual machines must be migrated off the affected datastore, or powered off, prior to running the below steps.

To disable ATSOnly on the VMFS5 datastore:

1. Connect to one of the hosts sharing the VMFS5 datastore with an SSH session. For more information, see
2. Run the following command:
   
   vmkfstools --configATSOnly 0 /vmfs/devices/disks/device-ID:Partition
   
   Where:
   
   device-ID is the NAA ID of the LUN on which the VMFS5 datastore was created.
   Partition is the partition number on which VMFS5 datastore was created. This is usually 1.
   
   For example:
   
   vmkfstools --configATSOnly 0 /vmfs/devices/disks/naa.6006016055711d00cef95e65664ee011:1
   
   Note: It is sufficient to run this command on one of the hosts sharing the VMFS5 datastore. Other hosts automatically recognize the change.
   
   
3. Run the following command to rescan for datastores:
   
   esxcli storage filesystem rescan
   
   
4. The VMFS5 datastore should now mount successfully.

Additional Information

For translated versions of this article, see:

• 日本語: ストレージ暗号化アプライアンスの使用時に VMFS5 データストアをマウントできない (2102378)