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DELL Power vault_MD3420 - Virtual disk not on preferred path error.

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DELL Power vault_MD3420 - Virtual disk not on preferred path error.

This question has been answered by DELL-Sam L

Hello Friends,

                         We have DELL MD3420 Power vault device with 2 SSD and 4 HDD. We've got an error message saying " Virtual disk not on preferred path". Can anyone please explain what is it ? 

Found below recovery step on the internet, 

    Redistribute virtual disks manually can fix this issue.

My doubt is that, this storage device has database running 24x7. Doing above recommandation wont distrub my database ? Whether any downtime or restart required if i Redistribute virtual disks manually ?

Please advise to clear this error.   

Verified Answer
  • Hello manicaps1,

    The alert on the system is due to a virtual disk not being on the preferred path. When virtual disks are created, they are assigned to one of the two controllers as a preferred communication path. If that path is not available – due to a network issue, controller reset, etc. – the array will communicate via the alternate controller. In some cases the communication does not shift back to the primary path when it becomes available again. To correct this you just need to manually redistribute the virtual disks back to their preferred paths.

    To redistribute virtual disks:

    1.           Open Modular Disk Storage Manager (MDSM)

    2.           Click on the Support tab

    3.           Select Manage Raid Controller Modules

    4.           Click on Redistribute Virtual Disks

    You will get an alert telling you that this will disrupt communications if you do not have the multipath drivers installed. You can ignore this message and proceed. If you still have access to the virtual disk that is not on preferred path, you have multipath drivers installed.

    Also, redistributing the virtual disk will not disturb the database as it is just moving the communication back to the owning controller of the virtual disk. There is no down time needed. If the error happens again then we may need to look at a support bundle from your MD3420 to ensure that there are no other issues.

    Please let us know if you have any other questions.

    DELL-Sam L
    Dell | Social Outreach Services - Enterprise
    Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)

All Replies
  • Hello manicaps1,

    The alert on the system is due to a virtual disk not being on the preferred path. When virtual disks are created, they are assigned to one of the two controllers as a preferred communication path. If that path is not available – due to a network issue, controller reset, etc. – the array will communicate via the alternate controller. In some cases the communication does not shift back to the primary path when it becomes available again. To correct this you just need to manually redistribute the virtual disks back to their preferred paths.

    To redistribute virtual disks:

    1.           Open Modular Disk Storage Manager (MDSM)

    2.           Click on the Support tab

    3.           Select Manage Raid Controller Modules

    4.           Click on Redistribute Virtual Disks

    You will get an alert telling you that this will disrupt communications if you do not have the multipath drivers installed. You can ignore this message and proceed. If you still have access to the virtual disk that is not on preferred path, you have multipath drivers installed.

    Also, redistributing the virtual disk will not disturb the database as it is just moving the communication back to the owning controller of the virtual disk. There is no down time needed. If the error happens again then we may need to look at a support bundle from your MD3420 to ensure that there are no other issues.

    Please let us know if you have any other questions.

    DELL-Sam L
    Dell | Social Outreach Services - Enterprise
    Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)

  • Thank you Mr.Sam. The issue has been fixed. 

  • Hi Mr.Sam,

                      Please be informed that I have got the same error message again. We checked all the physical connection and noted those are fine. Again I did redistribute the disks. What would be the next step of troubleshooting in this ? 

  • Hello manicaps1,

    How many virtual disk do you have on your MD3420? How many virtual disk are owned by each controller?

    Please let us know if you have any other questions.

    DELL-Sam L
    Dell | Social Outreach Services - Enterprise
    Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)

  • Hello Mr.Sam,

                           Please find the details as below, 

                           Disk Groups - 2 

                           RAID 1 Disk Groups - 1, Virtual disks - 4

                           RAID 5 Disk Groups - 1, Virtual disks - 1 

                           RAID 1_SSD (2 physical disks) - RAID Controller module in slot 0,1

                           RAID 5_HDD (4 physicak disks) - RAID Controller module in slot 1 

    Please check above details and provide me your suggession to proceed further to clear this error. Thanks a lot. 

  • Hello Mr.Sam,

                           Good day

                           Any update or solution for this error from you ?. FYI, we have 4 DELL MD3420 storages with same firmware versions and same kind of configurations in different regions around. But I've this error on one machine only. Also, all hardware wirings are checked and confirmed those are connected firmly. Is this happening because of any hardware failure ? Do I need to contact my local supplier here ? Kinldy check my previous details and support me in this regard.     

  • Hello manicaps1,

    In most cases when you are getting this error it is not a hardware issue. Can I get you to gather a support bundle so that we can review it to ensure that there is no hardware issue? I will send you an email that you can reply too with the support bundle.

    Please let us know if you have any other questions.

    DELL-Sam L
    Dell | Social Outreach Services - Enterprise
    Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)