Correlating VML ID with disk ID

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides information on finding the naa ID of the device from VML ID on the Storage array and decoding the content of VML ID.

This also applies to eui, SNS, & T10 as well, naa is just the most common

Environment

VMware vSphere ESXi (All Versions)

Resolution

Find the disk ID from the VML ID

To find the disk ID from the VML ID:

1. Run this command to find the associated VML ID for the LUN/storage device from the VMDK file name:
   
   #vmkfstools --queryrdm /vmfs/volumes/4d8008a2-9940968c-04df-001e4f1fbf2a/VM-BAISC/ABC.vmdk
   Disk /vmfs/volumes/4d8008a2-9940968c-04df-001e4f1fbf2a/node1/quorum.vmdk is a non Pass through Raw Device Mapping Maps to: vml.02000000006090a0a8e07bea184a0685b5f62efd94313030452d30
    
2. Correlate VML ID for the LUN with the associated LUN to find the disk ID.

For example, for a LUN with VML ID, vml.02000000006000eb3952315fbe000000000000001b695343534944,

the associated LUN is naa.6000eb3952315fbe000000000000001b , so the naa id of the LUN is 6000eb3952315fbe000000000000001b.

Decoding VML ID

The digits of the VML ID are divided into:

 

vml.      02      00      00      0000      6000eb3952315fbe000000000000001b            695343534944
AAAA   BB     CC     DD     EEEE     FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF    GGGGGGGGGGGG

Where:

 

A - represents the external ID name space.

B - represents uuid type for the device:

0x0 - For mpx.vmhbax:Cx:Tx:Lx format

0x1 - For serial number format

0x2 - For naa format

0x3 - For SYMM format

C - represents the device type:

0x00 - DISK

0x01 - TAPE

0x02 - PRINTER

0x03 - PROCESSOR /* HP scanners use this */

0x04 - WORM /* Treated as ROM by our system */

0x05 - ROM 0x05

0x06 - SCANNER

0x07 - MOD /* Magneto-optical disk - * - treated as TYPE_DISK */

0x08 - MEDIUM_CHANGER

0x09 - COMM /* Communications device */

0x0c - RAID

0x0d - ENCLOSURE 0x0d /* Enclosure Services Device */

0x0e - RBC 0x0e

0x7f - NO_LUN

D - represents LUN number (32 bits in normal device from SAN)

E - is reserved for future use

F - represents the LUN identifier (32 digit naa number in hexadecimal format)

G - A unique hash of other data about the LUN (In versions prior to 5.5 includes the LUN number)