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Resolving iSCSI LUN Discovery Failures on Windows Machines (KBA1613)






In some circumstances, SQL Server VDB Provisioning, Refresh or Enable operations may fail with one of the following error and action statements: 

Description: For the virtual database "DATABASE_NAME", failed to mount iSCSI LUNs from the Delphix Engine on target host "HOSTNAME".

or, in the case of enable,

Description: Failed to discover and mount LUNs from the Delphix Engine through the iSCSI initiator on target host "HOSTNAME"


Action: Make sure that the iSCSI initiator is running and that the user "USERNAME" has privileges to mount LUNs on the host.


Action: Make sure that the iSCSI initiator is running and that the user "USERNAME" has privileges to perform disk management on the host.

Applicable Delphix Versions 

Click here to view the versions of the Delphix engine to which this article applies
Major Release All Sub Releases





Troubleshooting Error "failed to mount iSCSI LUNs"

As part of linking and provisioning, the Delphix Engine presents disks LUNs to Windows Staging and Target hosts via iSCSI. The Delphix Engine then runs scripts on these hosts (using the native diskpart utility), to find the disks and mount them on the Windows machine.

The discovery process scans all configured SCSI devices for new disks. This operation typically completes in a few seconds, but may fail if some SCSI devices connected to the Windows host do not respond.

Check to make sure the iSCSI port 3260 is not blocked.  This is the iSCSI port listener on the Delphix engine and might be blocked on the Windows host firewall.

The Windows iSCSI Initiator applet (iscsicpl.exe) may help you identify iSCSI targets that are contributing to the "failed to mount iSCSI LUNs" error.

The Reconnecting... state shows that the Windows host is currently unable to reach some of its configured iSCSI targets, slowing down discovery:


Potential causes for the "Reconnecting..." state include:

  • The iSCSI Target is currently rebooting
  • The iSCSI Target is offline for maintenance
  • The iSCSI Target has changed IP addresses or been decommissioned and is no longer accessible

ResolutionEdit section

If some iSCSI Targets are stuck in a "Reconnecting..." state because they are no longer present, they should be removed from the list of iSCSI Target Portals on the affected Windows host.

  1. From the iSCSI Initiator, select the target in "Reconnecting" state and open its Properties:
  2. From the Properties tab, identify the Portal's IP address or hostname:
  3. Use the Disconnect button to stop the iSCSI connection attempt:
  4. From the Discovery tab, select the portal identified in Step 2, then use the Remove button to prevent future attempts to connect to that iSCSI Target:

If an iSCSI Target is required for the operation of a VDB, the Delphix Engine will automatically re-create any necessary configuration on the next VDB type operation involving the iSCSI mounting process (provision, refresh, rewind, enable, etc).