What is ESX VMID?

Overview

• The VMID is an integer that is associated with a given Virtual Machine and are assigned during initial frame exchanges between host and fabric.

Since this identifier is incorporated into the header of the FC frame, it allows any VMs that are associated with a given I/O path to be reported, end-to-end.

This allows the storage admin can easily identify any VMs that are stored on a given fabric in certain cases, without having to perform UUID lookup. 

• Various host-side commands can also be utilized that reference the VMID.

• If the target indicates the fact that it supports VMID during login, the host will transmit these IDs to the target. This can happen in one of two possible ways: 

1. Application Header mechanism, which involves the usage of an optional header, and the

2. Priority Tagging mechanism, which utilizes an existing field in the typical frame header. 

• The target will then utilize any host-assigned identifiers that it receives in its response frames.

Configuration

• Aside from versioning, no configuration actions are necessary on the NetApp storage device.

Application Header Example:

Command:

esxcli elxfc vmid get -n vmhba5

lpfc VMID page: on

ID00 READs:000000000000051e WRITEs:00000000000000d2

     UUID: 35302033362035342064652032302065312038342065302d6136206232203634206234206665203436203032206430

     String (50 36 54 de 20 e1 84 e0-a6 b2 64 b4 fe 46 02 d0)

     Application id: x209

     Last access time: 2020-01-26T14:59:16

     Compressed: 503654de20e184e0a6b264b4fe4602d0

ID01 READs:00000000000006d8 WRITEs:0000000000000191

     UUID: 35302033362064312033302063312030652066372037362d3532206363203439206464203537206339203162206165

     String (50 36 d1 30 c1 0e f7 76-52 cc 49 dd 57 c9 1b ae)

     Application id: x10

     Last access time: 2020-01-26T14:59:32

     Compressed: 5036d130c10ef77652cc49dd57c91bae

On Brocade Switch:
Command:

appserver --show -domain 17

Output:

------------------------------------------------------------

Displaying results for Domain 0x11 (17)

------------------------------------------------------------

N_Port ID         : 111a00

Entity ID (ASCII) : 52 eb 8a e3 7b c6 f9 69-ef 56 d3 3a ba ca 04 cc

Entity ID (Hex)   : 0x35322065622038612065332037622063362066392036392d6566203536206433203361206261206361203034206363

Application ID    : 0x00000010h (16)

--------------------

N_Port ID         : 111a00

Entity ID (ASCII) : 52 96 01 b3 83 5d 3a e0-24 c7 bf 6a 86 11 2e a2

Entity ID (Hex)   : 0x35322039362030312062332038332035642033612065302d3234206337206266203661203836203131203265206132

Application ID    : 0x00000209h (521)

--------------------

Application Server displays 2 entries

Priority Tagging Example:

Command:

esxcli elxfc vmid get -n vmhba3

lpfc VMID page: on

VMID priority ranges:

        [x1 - x60], qos: x0

VEM ID: 10:00:00:90:fa:d1:59:c1:20:00:00:90:fa:d1:59:c1

 ID00 READs:0000000000002e5e WRITEs:000000000000066c

     UUID: 35302033362039372062322033652034302066352036622d6332206434203261203739206337206237203262203763

     String (50 36 97 b2 3e 40 f5 6b-c2 d4 2a 79 c7 b7 2b 7c)

     CS_CTL VMID: x1

     Last access time: 2020-02-17T09:25:35

     Compressed: 503697b23e40f56bc2d42a79c7b72b7c

ID01 READs:00000000000009e1 WRITEs:0000000000000028

     UUID: 35302030352062622037622031322035332037612031332d3630203630203564203734203938203936203437203439

     String (50 05 bb 7b 12 53 7a 13-60 60 5d 74 98 96 47 49)

     CS_CTL VMID: x2

     Last access time: 2020-02-17T09:25:18

     Compressed: 5005bb7b12537a1360605d7498964749

On Cisco Switch:
Command:

show vmis database

Total 2 entries

-----------------------------------------------------------------------------

INTERFACE         VSAN  FCID      LOCAL VEID           GLOBAL VEID

-----------------------------------------------------------------------------

--                6     0xe702c0            0x01        52e3962f-1d6a-144a-c228-3f97ac724c1e

--                6     0xe702c0            0x02        5230a093-cb42-ef72-6b5f-91b273bd1b92