Use the vmkfstools command to create a VMFS datastore.

-C --createfs [vmfs3|vmfs5]
      -b --blocksize block_size kK|mM
      -S --setfsname datastore

This option creates a VMFS3 or VMFS5 datastore on the specified SCSI partition, such as disk_ID:P. The partition becomes the file system's head partition.


Use the VMFS3 option when you need legacy hosts to access the datastore.

You can specify the following suboptions with the -C option:

  • -b --blocksize – Define the block size for the VMFS datastore.

    For VMFS5, the only available block size is 1MB. For VMFS3, the default block size is 1MB. Depending on your needs, the block size can be 1MB, 2MB, 4MB, and 8MB. When you enter the size, indicate the unit type by adding a suffix, such as m or M. The unit type is not case sensitive.

  • -S --setfsname – Define the volume label of the VMFS datastore you are creating. Use this suboption only in conjunction with the -C option. The label you specify can be up to 128 characters long and cannot contain any leading or trailing blank spaces.


    vCenter Server supports the 80 character limit for all its entities. If a datastore name exceeds this limit, the name gets shortened when you add this datastore to vCenter Server.

    After you define a volume label, you can use it whenever you specify the VMFS datastore for the vmkfstools command. The volume label appears in listings generated for the ls -l command and as a symbolic link to the VMFS volume under the /vmfs/volumes directory.

    To change the VMFS volume label, use the ln -sf command. Use the following as an example:

    ln -sf /vmfs/volumes/UUID /vmfs/volumes/datastore

    datastore is the new volume label to use for the UUID VMFS.


    If your host is registered with the vCenter Server, any changes you make to the VMFS volume label get overwritten by the vCenter Server. This guarantees that the VMFS label is consistent across all vCenter Server hosts.