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Obtaining LUN pathing information for ESX or ESXi hosts (1003973)

Purpose

This article explains using tools to determine LUN pathing information for ESX hosts.

Resolution

There are two methods used to obtain the multipath information from the ESX host:
  • ESX command line – use the command line to obtain the multipath information when performing troubleshooting procedures.
  • VMware Infrastructure/vSphere Client – use this option when you are performing system maintenance.

ESXi 5.x / ESXi 5.5

Command line

To obtain LUN multipathing information from the ESXi host command line:
  1. Log in to the ESXi host console.
  2. Type esxcli storage core path list to get detailed information regarding the paths. For example:

    fc.5001438005685fb7:5001438005685fb6-fc.5006048c536915af:5006048c536915af-naa.60060480000290301014533030303130
       UID: fc.5001438005685fb7:5001438005685fb6-fc.5006048c536915af:5006048c536915af-naa.60060480000290301014533030303130
       Runtime Name: vmhba1:C0:T0:L0
       Device: naa.60060480000290301014533030303130
       Device Display Name: EMC Fibre Channel Disk (naa.60060480000290301014533030303130)
       Adapter: vmhba1
       Channel: 0
       Target: 0
       LUN: 0
       Plugin: NMP
       State: active
       Transport: fc
       Adapter Identifier: fc.5001438005685fb7:5001438005685fb6
       Target Identifier: fc.5006048c536915af:5006048c536915af
       Adapter Transport Details: WWNN: 50:01:43:80:05:68:5f:b7 WWPN: 50:01:43:80:05:68:5f:b6
       Target Transport Details: WWNN: 50:06:04:8c:53:69:15:af WWPN: 50:06:04:8c:53:69:15:af


  3. Type esxcli storage core path list -d <naaID>   to list the detailed information of the corresponding paths for a specific device.

  4. The command esxcli storage nmp device list lists of LUN multipathing information:

    naa.60060480000290301014533030303130
       Device Display Name: EMC Fibre Channel Disk (naa.60060480000290301014533030303130)
       Storage Array Type: VMW_SATP_SYMM
       Storage Array Type Device Config: SATP VMW_SATP_SYMM does not support device configuration.
       Path Selection Policy: VMW_PSP_FIXED
       Path Selection Policy Device Config: {preferred=vmhba0:C0:T1:L0;current=vmhba0:C0:T1:L0}
       Path Selection Policy Device Custom Config:
       Working Paths: vmhba0:C0:T1:L0


    Notes:

vSphere Client

To obtain multipath settings for your storage in vSphere Client:

  1. Select an ESX/ESXi host, and click the Configuration tab.
  2. Click Storage.
  3. Select a datastore or mapped LUN.
  4. Click Properties.
  5. In the Properties dialog, select the desired extent, if necessary.
  6. Click Extent Device > Manage Paths and obtain the paths in the Manage Path dialog.
For information on multipathing options, see Multipathing policies in ESXi 5.x and ESXi/ESX 4.x (1011340).

ESX 4.x

Command line

To obtain LUN multipathing information from the ESX/ESXi host command line:
  1. Log in to the ESX host console.
  2. Type esxcfg-mpath -b to list all devices with their corresponding paths:

    naa.6006016095101200d2ca9f57c8c2de11: DGC Fibre Channel Disk (naa.6006016095101200d2ca9f57c8c2de11)
    vmhba3:C0:T0:L0 LUN:0 state:active fc Adapter: WWNN: 20:00:00:1b:32:86:5b:73 WWPN: 21:00:00:1b:32:86:5b:73 Target: WWNN: 50:06:01:60:b0:20:f2:d9 WWPN: 50:06:01:60:b0:20:f2:d9
    vmhba3:C0:T1:L0 LUN:0 state:active fc Adapter: WWNN: 20:00:00:1b:32:86:5b:73 WWPN: 21:00:00:1b:32:86:5b:73 Target: WWNN: 50:06:01:60:b0:20:f2:d9 WWPN: 50:06:01:60:b0:20:f2:d9

    The device " naa.6006016095101200d2ca9f57c8c2de11" has 2 paths: vmhba3:C0:T0:L0 and vmhba3:C0:T1:L0 .

  3. Type esxcfg-mpath -l to get more detailed information regarding the paths. For example:

    fc.2000001b32865b73:2100001b32865b73-fc.50060160c6e018eb:5006016646e018eb-naa.6006016095101200d2ca9f57c8c2de11
    Runtime Name: vmhba3:C0:T1:L0
    Device: naa.6006016095101200d2ca9f57c8c2de11
    Device Display Name: DGC Fibre Channel Disk (naa.6006016095101200d2ca9f57c8c2de11)
    Adapter: vmhba3 Channel: 0 Target: 1 LUN: 0
    Adapter Identifier: fc.20000000c98f3436:10000000c98f3436
    Target Identifier: fc.50060160c6e018eb:5006016646e018eb
    Plugin: NMP
    State: active
    Transport: fc
    Adapter Transport Details: WWNN: 20:00:00:1b:32:86:5b:73 WWPN: 21:00:00:1b:32:86:5b:73
    Target Transport Details: WWNN: 50:06:01:60:b0:20:f2:d9 WWPN: 50:06:01:60:b0:20:f2:d9


  4. The command esxcli nmp device list lists of LUN multipathing information:

    naa.6006016010202a0080b3b8a4cc56e011
    Device Display Name: DGC Fibre Channel Disk (naa.6006016010202a0080b3b8a4cc56e011)
    Storage Array Type: VMW_SATP_ALUA_CX
    Storage Array Type Device Config: {navireg=on, ipfilter=on}{implicit_support=on;explicit_support=on; explicit_allow=on;alua_followover=on;{TPG_id=2,TPG_state=ANO}{TPG_id=1,TPG_state=AO}}
    Path Selection Policy: VMW_PSP_FIXED_AP
    Path Selection Policy Device Config: {preferred=vmhba3:C0:T1:L0;current=vmhba3:C0:T1:L0}
    Working Paths: vmhba3:C0:T1:L0

    The Path Selection Plug-Ins (PSP) policy is what ESX host uses when it determines which path to use in the event of a failover. Supported PSP options are:

    VMW_PSP_FIXED Fixed Path Selection
    V
    MW_PSP_MRU Most Recently Used Path Selection
    VMW_PSP_RR Round Robin Path Selection
    VMW_PSP_FIXED_AP Fixed Path Selection with Array Preference (introduced in ESX 4.1)

    Note:
    For information on multipathing and path selection options, see Multipathing policies in ESXi 5.x and ESXi/ESX 4.x (1011340).

vSphere Client

To obtain multipath settings for your storage in vSphere Client:

  1. Select an ESX/ESXi host, and click the Configuration tab.
  2. Click Storage.
  3. Select a datastore or mapped LUN.
  4. Click Properties.
  5. In the Properties dialog, select the desired extent, if necessary.
  6. Click Extent Device > Manage Paths and obtain the paths in the Manage Path dialog.
For information on multipathing options, see Multipathing policies in ESXi 5.x and ESXi/ESX 4.x(1011340).

ESX 3.x

Command line

To obtain LUN multipathing information from the ESX host command line:
  1. Log in to the ESX host console.
  2. Type esxcfg-mpath -l and press Enter.

    The output appears similar to the following:

    Disk vmhba2:1:4 /dev/sdh (30720MB) has 2 paths and policy of Most Recently Used

    FC 10:3.0 210000e08b89a99b<-> 5006016130221fdd vmhba2:1:4 On active preferred
    FC 10:3.0 210000e08b89a99b<-> 5006016930221fdd vmhba2:3:4 Standby

    Disk vmhba2:1:1 /dev/sde (61440MB) has 2 paths and policy of Most Recently Used

    FC 10:3.0 210000e08b89a99b<->5006016130221fdd vmhba2:1:1 On active preferred
    FC 10:3.0 210000e08b89a99b<->5006016930221fdd vmhba2:3:1 Standby


    In this example, two LUNs are presented.

    As there are no descriptions given, here is an analysis of the information provided for the first LUN:
    • vmhba2:1:4 - This is the canonical device name the ESX host used to refer to the LUN.

      Note
      : When there are multiple paths to a LUN, the canonical name is the first path that was detected for this LUN.

    • /dev/sdh - This is the associated Linux device handle for the LUN. You must use this reference when using utilities like fdisk.
    • 30720MB - The disk capacity of the LUN, e.g 30720MB or 30GB.
    • Most Recently Used - This is the policy the ESX host uses when it determines which path to use in the event of a failover. The choices are:
      • Most Recently Used: The path used by a LUN is not be altered unless an event (user, ESX host, or array initiated) instructs the path to change. If the path changed because of a service interruption along the original path, the path does not fail-back when service is restored. This policy is used for Active/Passive arrays and many pseudo active/active arrays.
      • Fixed: The path used by a LUN is always the one marked as preferred, unless that path is unavailable. As soon as the path becomes available again, the preferred becomes the active path again. This policy is used for Active/Active arrays. An Active/Passive array should never be set to Fixed unless specifically instructed to do so. This can lead to path thrashing, performance degradations and virtual machine instability.
      • Round Robin: This is experimentally supported in ESX 3.x. It is fully supported in ESX 4.x.

        Note: See the Additional Information section for references to the arrays and the policy they are using


    • FC - The LUN disk type. There are three possible values for LUN disk type:
      • FC: This LUN is presented through a fibre channel device.
      • iScsi: This LUN is presented through an iSCSI device
      • Local: This LUN is a local disk

    • 10:3.0 - This is the PCI slot identifier, which indicates the physical bus location this HBA is plugged into.
    • 210000e08b89a99b - The HBA World Wide Port Names (WWPN) are the hardware addresses (much like the MAC address on a network adapter) of the HBAs.
    • 5006016930221fdd - The Storage processor port World Wide Port Names (WWPN) are the hardware addresses of the ports on the storage processors of the array.
    • vmhba2:1:4 - This is the true name for this path. In this example, there are two possible paths to the LUN ( vmhba2:1:4 and vmhba2:3:4 ).
    • On active preferred - The Path status contains the status of the path. There are six attributes that comprise the status:
      • On: This path is active and able process I/O. When queried, it returns a status of READY.
      • Off: The path has been disabled by the administrator.
      • Dead: This path is no longer available for processing I/O. This can be caused by physical medium error, switch, or array misconfiguration.
      • Standby: This path is inactive and cannot process I/O. When queried, it returns a status of NOT_READY
      • Active: This path is processing I/O for the ESX Server host
      • Preferred: This is the path that is preferred to be active. This attribute is ignored when the policy is set to Most Recently Used (mru).

  3. VI Client

    To obtain multipathing information from VI Client:
    1. Select an ESX host.



    2. Click the Configuration tab.



    3. Click Storage.



    4. Click the VMFS-3 datastore you are interested in.



    5. Click Properties.



      The following dialog appears:



      From this example, you can see that the canonical name is vmhba2:1:0 and the true paths are vmhba2:1:0 and vmhba2:3:0 .
      The active path is vmhba2:1:0 and the policy is Most Recently Used.

    6. Click Manage Paths. The Manage Paths dialog appears:


Additional Information

For more information, see the documentation for your version of ESX and consult the Storage/SAN Compatibility Guide.

For more information on ESXi 5.5, see the VMware vSphere 5.5 Documentation Center

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Tags

lun-presentation lun-paths

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