Windows Server 2019 iSCSI connection was working LUN no longer presents a volume to windows

microchipmatt 6 Reputation points

I have a Windows Server 2019 server that WAS connected to a JetStor iSCSI target. The LUN on the JetStor is set up for read and write access, and the Windows Server 2019 Server was connected to the Target, and the Volume for the LUN on the JetStor WAS presented to windows and then Viewable in Computer Management-->Storage-->Disk Management. The LUN is set up for Any host to access it with read-and-write access


I used the iscsi connection and LUN on the server for about 1 week, and then the Volume....Disappeared. I rebooted the server, double-checked the iSCSI connection and sure enough, the iSCSI connection was still connected....However, now the LUN Target presents no Volumes to windows to Map, hence it not showing up in Computer Management anymore. The Lun is still available for read and write access, but once again no volume is presented to Windows Server 2019:

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Under Devices, no volume data for the LUN, it remains blank:

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Hitting autoconfigure presents no volume as well:

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As you can see there is even an active connection, and the Windows Server 2019 initator is viewable and the connection

is active, but still noe volume for the lun:

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But as shown above, no volume presented Windows in the LUN for connection. Has anyone seen this before, any idea on how to rectify this?

Windows Server
Windows Server
A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.
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  1. Alex Bykovskyi 1,681 Reputation points


    In iSCSI initiator LUN shows with -1 number. I faced similar issue. You can try checking the following:

    • open regedit
    • navigate to HKLM\System\CurrentControlSet\Services\msdsm\Parameters\DsmSupportedDeviceList
    • edit DsmSupportedDeviceList and verify that Value data got lines below:
    • Vendor 8Product 16
    • MSFT2005iSCSIBusType_0x9

    Might also help:

    In addition, you can try create another iSCSI Target with StarWind VSAN (free version can be used) and try connecting to it.

    Alex Bykovskyi 
    StarWind Software 
    Note: Posts are provided “AS IS” without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

    1 person found this answer helpful.

  2. Limitless Technology 43,921 Reputation points


    Thank you for your question and reaching out. I can understand you are having query\issues related to

    1. Verify that the initiator is logged in to the storage system. If the iscsi initiator show command output shows no initiators are logged in, check the initiator configuration on the host. Also verify that the storage system is configured as a target of the initiator.
    2. Enable Multiple on iSCSI Initiator.
    3. Please Verify that the LUNs are mapped to an igroup. On the storage system console, you can use one of the following commands:

    lun mapping show displays all LUNs and the igroups to which they are mapped.

    lun mapping show -igroup displays the LUNs mapped to a specific igroup.

    1. Update or ReInstall NIC drivers on Server.
    2. Disable any Antivirus program or Windows firewall you may have for temporary purpose.
    3. Please check Event Log on the Server for any further clue.
    4. If issue still persists then please try to reach out to JetStor support.

    --If the reply is helpful, please Upvote and Accept as answer--

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