Enabling CAW on a datastore using the ESXi CLI

If you did not have support for Compare and Write (CAW) in Data ONTAP operating in 7-Mode, you must manually enable CAW support when you transition to clustered Data ONTAP. Clustered Data ONTAP supports CAW by default.

Before you begin

There must be no I/O or VMs actively running on the VMFS datastore.
The datastore must be remounted, if it was migrated.
You must have the new ONTAP LUN naa ID from the 7-Mode Transition Tool (7MTT) mapping file.

About this task

CAW must be enabled only when no I/O or VMs are actively running on the VMFS datastore.

CAW must be enabled only when no I/O or VMs are actively running on the VMFS datastore.
For copy-based transitions, perform these steps after completing the Storage cutover operation in the 7MTT.
For copy-free transitions, perform these steps after the Import Data & Configuration operation in the 7MTT is complete.

Procedure

Open the Inventory Assessment Workbook generated by the Inventory Collect Tool (ICT).
Navigate to the SAN Host Filesystems tab.
Verify the CAW status for the datastore.
The ATS/CAW value for the datastore should display Disabled, and the Filesystem column should display VMFS.x.
Note the name of the datastore in the Disk column
Log in to the ESXi console using SSH.

List the device and partition details: ~ # vmkfstools -Ph -v1 datastore_path

datastore_path is the datastore name from the Disk column of the Inventory Assessment Workbook.

# vmkfstools -Ph -v1 /vmfs/volumes/datastorename

VMFS-5.60 file system spanning 1 partitions.
File system label (if any): datastorename
Mode: public
Capacity 9.8 GB, 8.2 GB available, file block size 1 MB, max file size 64
TB
Volume Creation Time: Mon Dec 9 10:29:18 2013
Files (max/free): 27408/27394
Ptr Blocks (max/free): 64512/64495
Sub Blocks (max/free): 3968/3964
Secondary Ptr Blocks (max/free): 256/256
File Blocks (overcommit/used/overcommit %): 0/1593/0
Ptr Blocks (overcommit/used/overcommit %): 0/17/0
Sub Blocks (overcommit/used/overcommit %): 0/4/0
Volume Metadata size: 590675968
UUID: 52a59b7e-52d2fb6c-11d6-001ec9d631cb
Partitions spanned (on "lvm"):
naa.600a098044314c6c442b446d51376749:1
naa.600a098054314c6c445d446f79716431:1
naa.600a098054314c6c445d446f79716433:1
Is Native Snapshot Capable: YES

Note the first device name and partition number.
In the preceding example, naa.600a098044314c6c442b446d51376749:1 is the device name and partition number.
Use the device ID and partition number to enable CAW on the datastore: ~# vmkfstools --configATSOnly 1 /vmfs/devices/disks/device-ID:Partition
Verify that the VMFS volume has been configured with ATS only: # vmkfstools -Ph -v1 /vmfs/volumes/VMFS-volume-name
```
VMFS-5.54 file system spanning 1 partitions.
File system label (if any): ats-test-1
Mode: public ATS-only
```