PowerVault MD3000 / MD3000i - Troubleshooting Steps for when a Virtual Disk is not on the Preferred Path

PowerVault MD3000 / MD3000i - Troubleshooting Steps for when a Virtual Disk is not on the Preferred Path


Article Summary: This article provides information on the "PowerVault MD3000 / MD3000i - Troubleshooting Steps for when a Virtual Disk is not on the Preferred Path".

Table of Contents:
  1. Situation
  2. General Troubleshooting


Issue 1.


Situation


Virtual Disk not on Preferred Path

What Caused the Problem?

There is a problem accessing the RAID controller module listed in the Recovery Guru Details Area.
Any virtual disks that have this RAID controller module assigned as their preferred path will be
moved to the non-preferred path (alternate RAID controller module).

The following procedure below will help you pinpoint the problem along the data path.
Because the virtual disks will be moved to the alternate RAID controller module,
they should still be accessible. Therefore, no action is required on the individual virtual disks.

Possible causes include:
  • The RAID controller module failed a manually initiated diagnostic test and was placed Offline.
  • The RAID controller module was manually placed Offline or is in Service Mode.
  • There are disconnected or faulty cables.
  • A host adapter has failed.
  • The storage array contains a defective RAID controller module.


Issue 2.


General
Troubleshooting


Notice:
Possible Loss of Data Access. Do not replace the RAID controller module until you are instructed to do so. This procedure will instruct you to check the components along the connection, check the host adapters, and eventually instruct you to replace the RAID controller module, if necessary.

Notice:
Electrostatic discharge can damage sensitive components. Always use proper antistatic protection when handling components. Touching components without using a proper ground may damage equipment.

Link: Learn how to Avoid ESD Damage

Note:
It can take several minutes for the host-based, multi-path failover driver to recognize a restored or modified preferred path. A Virtual Disk Not On Preferred Path error will be reported during this time.

If you have recently modified the preferred path by clicking the Change virtual disk ownership/preferred path link from the Modify tab, or you performed a recovery procedure that has restored a preferred path, wait at least 10 minutes and run the Recovery Guru again by clicking the Recheck button.

If the error is presented again, use the following steps below:

The Recovery Guru is a component of MDSM (Modular Disk Storage Manager) that assists
with the critical events on the storage array, and provides steps for possible recovery and resolution.

You can access the Recovery Guru by clicking the Storage Array Needs Attention link
on the Summary page or by clicking the Recover from failure link on the Support page.

Begin troubleshooting a Virtual Disk not on a Preferred Path by determining,
if the RAID Controller was placed offline or in service mode.
The Recovery GURU instructed the controller be placed offline or in service mode.
  1. Ensure the steps recommended by the Recovery Guru were completed
    (Complete the steps if they have not been done).
  2. Rerun the Recovery GURU. If the Virtual Disk is still not on the Preferred Path,
    please contact Dell Technical Support.

The controller was manually placed offline or in service mode,
but this was not instructed by the Recovery GURU.
  1. Place the RAID Controller offline.
  2. Rerun the Recovery GURU.
    If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.

The controller is offline, but not placed offline.

Troubleshoot the offline Raid Controller.
The MD3000 RAID Controller (SAS) is online.
  1. Verify that the MD3000 is cabled correctly, all connections are fully seated,
    and no cables or connectors are damaged.
    If connections have to be fixed, rerun the Recovery Guru after fixing the connections.
    If the Virtual Disk is still not on the Preferred Path after fixing the bad connections, please contact Dell Technical Support.
  2. Determine how the MD3000 is connected.
    1. The host has a connection to only one of the array controllers
      and the virtual disk is not assigned to that controller.
      1. Stop all the Input/Output (I/O) to the RAID controller.
      2. Redistribute the Virtual Disks in Storage Manager.
      3. Change the Virtual Disk Preferred path in Storage Manager.
      4. Rerun the Recovery GURU.
      5. If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.
    2. The host is connected to both controllers.
      1. Verify the Host is operational (completed POST and the operating system has fully loaded with no errors).
        Troubleshoot any issues with the Host before proceeding.
      2. Verify the SAS 5/E or SAS 6/E appears during POST with no errors and the port status LED is not amber.
        Troubleshoot any issues with the controller before proceeding.
      3. Place the RAID controller offline in Storage Manager.
      4. If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.
    3. This is an initial deployment in a clustered environment.
      1. Redistribute the Virtual Disks in Storage Manager.
      2. Rerun the Recovery GURU.
        If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.

The MD3000i RAID Controller (iSCSI) is online
Determine how the MD3000i is attached.

The MD3000i is switch attached.
Check the Link Status on the iSCSI ports on the MD3000i and on the NIC on the Host.
The Link Status is good. PING the iSCSI Host Ports, as follows:
  1. Ping the iSCSI HOST
    1. Open a command line.
    2. Move to the directory containing SMI.exe
      (The default location is C:\Program Files\Dell|MD Storage Manager\client).
    3. At the command line type ping [xxx.xxx.xxx.xxx] and press the <Enter> key, where [xxx.xxx.xxx.xxx]
      is the IP address of one of the iSCSI controllers on the host.
      An unsuccessful ping returns the IP address.
    4. Repeat step 3 with the address of the second iSCSI controller.
  2. The PING is unsuccessful.
    1. Check the IP configuration.
    2. Verify any Virtual LANs (VLANs) are set up correctly.
    3. Verify Jumbo Frames are set up correctly.
    4. Rerun the Recovery GURU.
      If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.
  3. The PING is successful. Determine how the MD3000i is attached.
    1. The MD3000i is connected to both controllers.
      1. Establish iSCSI sessions to both controllers.
      2. Verify CHAP is set up correctly.
      3. Verify the Initiator is setup correctly.
        If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.
    2. The MD3000i is connected to a single controller.
      1. Stop all the Input/Output (I/O) to the RAID controller.
      2. Redistribute the Virtual Disks in Storage Manager.
      3. Change the Virtual Disk Preferred path in Storage Manager.
        Rerun the Recovery GURU. If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.


If the Link Status is bad. Confirm the rest of the network is functioning properly.
This should include:
  1. Verifying the NIC (Network Interface Card) in the host is functioning correctly
  2. Verifying all cables are good
  3. Verifying the switch or router ports are passing traffic
  4. Verifying traffic is being routed correctly
  5. Verifying traffic is not being blocked by any firewalls

    If no issues are found with the network, replace the RAID controller by Hot Swapping.
    If issues are found with the network, fix the issue. then rerun the Recovery GURU.
    If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.

    The MD3000i is switch directly attached to the host.
    Check the Link Status on the iSCSI ports on the MD3000i and on the NIC on the Host.
    The Link Status is good.

    PING the iSCSI Host Ports
    .
    1. Ping the iSCSI HOST
    2. Open a command line.
    3. Move to the directory containing SMI.exe (The default location is C:\Program Files\Dell|MD Storage Manager\client).
    4. At the command line type ping [xxx.xxx.xxx.xxx] and press the <Enter> key, where [xxx.xxx.xxx.xxx] is the IP address
      of one of the iSCSI controllers on the host. An unsuccessful ping returns the IP address.
    5. Repeat step 3 with the address of the second iSCSI controller.

The PING is unsuccessful.
  1. Check the IP configuration.
  2. Verify any Virtual LANs (VLANs) are set up correctly.
  3. Verify Jumbo Frames are set up correctly.

Rerun the Recovery GURU.
If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.


The PING is successful.

Again, determine how the MD3000i is attached.
  1. The MD3000i is connected to both controllers.
    1. Establish iSCSI sessions to both controllers.
    2. Verify CHAP is set up correctly.
    3. Verify the Initiator is setup correctly.
      If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.
  2. The MD3000i is connected to a single controller.
    1. Stop all the Input/Output (I/O) to the RAID controller.
    2. Redistribute the Virtual Disks in Storage Manager.
    3. Change the Virtual Disk Preferred path in Storage Manager.
      Rerun the Recovery GURU. If the Virtual Disk is still not on the Preferred Path,
      please contact Dell Technical Support.
  3. If the Link Status is bad.
    Confirm the rest of the network is functioning properly.
    This should include:
    1. Verifying the NIC in the host is functioning correctly
    2. Verifying all cables are good
    3. Verifying the switch or router ports are passing traffic
    4. Verifying traffic is being routed correctly
    5. Verifying traffic is not being blocked by any firewalls
If no issues are found with the network, replace the RAID controller by Hot Swapping.
If issues are found with the network, fix the issue. then rerun the Recovery GURU.
If the Virtual Disk is still not on the Preferred Path, please contact Dell Technical Support.

Note:
Consider using the following link, if necessary, assist with explanation of some of the troubleshooting steps:

Link: PowerVault MD3000i - General Troubleshooting Steps for Communication Issues
 



Quick Tips content is self-published by the Dell Support Professionals who resolve issues daily. In order to achieve a speedy publication, Quick Tips may represent only partial solutions or work-arounds that are still in development or pending further proof of successfully resolving an issue. As such Quick Tips have not been reviewed, validated or approved by Dell and should be used with appropriate caution. Dell shall not be liable for any loss, including but not limited to loss of data, loss of profit or loss of revenue, which customers may incur by following any procedure or advice set out in the Quick Tips.

ID del artículo: SLN163937

Última fecha de modificación: 05/31/2018 05:36 PM


Valorar este artículo

Acertado
Útil
Fácil de entender
¿Le ha resultado útil este artículo?
No
Envíenos sus comentarios
Los comentarios no pueden contener caracteres especiales: <>()\
Lo sentimos. El sistema de envío de comentarios no está operativo en estos momentos. Vuelva a intentarlo más tarde.

Gracias por sus comentarios