Configure VMFS filesystem on USB disk and mount it as datastore on ESXi host

Home > VMWare platform > VMWare vSphere or ESXi > Configure VMFS filesystem on USB disk and mount it as datastore on ESXi host

To configure a USB based disk as datastore to store VMs or other ESXi files use following steps:

1. Start SSH service on ESXi host if not started already
2. Connect to ESXi host over SSH
3. Stop and disable USB arbitrator service using:

   /etc/init.d/usbarbitrator stop
   chkconfig usbarbitrator off

   usbarbitrator is required if we want to Raw Device Mapping (RDM) and map a USB connected to ESXi host to a VM. We cannot do both map a USB to VM and use USB as datastore on ESXi at the same time. Only one of the two is possible.

4. Get the list of device names:

   ls /dev/disks/ #OR
   vdq -q

   Same should also be available when we open ESXi host via web UI (Storage -> Devices)

   Copy the device name of USB disk (naa.* or mpx.*) to some temporary location (eg Text file)

   Example output

   {
   "Name"     : "mpx.vmhba32:C0:T0:L0",
   "VSANUUID" : "",
   "State"    : "Ineligible for use by VSAN",
   "Reason"   : "Has partitions",
   "IsSSD"    : "0",
   "IsCapacityFlash": "0",
   "IsPDL"    : "0",
   "Size(MB)" : "1907729",
   "FormatType" : "512n",
   "IsVsanDirectDisk" : "0",
   },

5. Create gpt partition table (label) on recognized disk using:

   partedUtil mklabel /dev/disks/<disk-device-name> gpt

   Example 'partedUtil mklabel /dev/disks/mpx.vmhba32:C0:T0:L0 gpt'

6. Once partition table is created we can create partition for that to figure out end sector use:

   partedUtil getptbl /dev/disks/<disk-device-name>

   From output take the last value and subtract 2048. For example if output is:

   gpt
   243201 255 63 3907029168

   The calculation would lead to last sector being = 3907029168 - 2048 = 3907027120

   All the reference links below are wrong. Please see VMWare official KB on partedUtil getptbl command at https://kb.vmware.com/s/article/1036609 We should subtract 2048 from the last value shown by the command.

7. Get the GUID of VMFS datastore using:

   partedUtil showGuids

   It should be 'AA31E02A400F11DB9590000C2911D1B8'

8. Create partition using command:

   partedUtil setptbl /dev/disks/<disk-device-name> gpt "1 2048 <end-sector> AA31E02A400F11DB9590000C2911D1B8 0"

   Example 'partedUtil setptbl /dev/disks/mpx.vmhba32:C0:T0:L0 gpt "1 2048 3907027120 AA31E02A400F11DB9590000C2911D1B8 0"'

9. Format the USB file-system and give it desired name using:

   vmkfstools -C vmfs6 -S <name> /dev/disks/<deviceID>:1

   For example 'vmkfstools -C vmfs6 -S USB-2TB-SSD-datastore /dev/disks/mpx.vmhba32:C0:T0:L0:1'

10. The datastore should now be visible in web UI. You can also see it mounted under /vmfs/volumes

Note that there is comment about large drives (>2TB) not working on ESXi 6.5 in first reference link.

Refer:

• https://www.virten.net/2016/11/usb-devices-as-vmfs-datastore-in-vsphere-esxi-6-5/
• https://vmscrub.com/creating-a-vmfs-datastore-on-a-usb-drive/
• https://www.it-react.com/index.php/2020/04/26/how-to-add-a-usb-disk-as-vmfs-datastore-in-esxi-6-7/

Connecting USB with existing VMFS datastore to ESXi host

It is possible that USB with existing VMFS datastore is not getting recognized in ESXi host automatically. In that case use:

1. Get the name of USB disk which is getting recognized erroneously as snapshot:

   esxcli storage vmfs snapshot list

   Example output

   583b1a72-ade01532-55f6-f44d30649051
   Volume Name: usbflash
   VMFS UUID: 583b1a72-ade01532-55f6-f44d30649051
   Can mount: true
   Reason for un-mountability:
   Can resignature: true
   Reason for non-resignaturability:
   Unresolved Extent Count: 1

2. Use the VMFS UUID to mount the datastore:

   esxcli storage vmfs snapshot mount -u <uuid>

   For example

   esxcli storage vmfs snapshot mount -u 583b1a72-ade01532-55f6-f44d30649051

Refer:

• https://www.virten.net/2016/11/usb-devices-as-vmfs-datastore-in-vsphere-esxi-6-5/

Home > VMWare platform > VMWare vSphere or ESXi > Configure VMFS filesystem on USB disk and mount it as datastore on ESXi host