Dell EqualLogic Group Manager throws an error "Request target not found" after successful backup

After a successful backup of VMs stored on Dell EqualLogic storage (especially when the option Allow processing of multiple VMs with a single volume snapshot is enabled) you may receive an error in Group Manager “iSCSI login to target ‘X.X.X.X:Y’  from  initiator ‘X:X:X:X::Z’ failed for following reason: Request target not found”.

Microsoft Volume shadow copy service (VSS) invokes OnLunEmpty method to the hardware provider when it receives a delete request on the snapshot.  The EqualLogic VSS hardware provider does the iSCSI session logoff of the snapshot, offlines the snapshot, and then deletes the snapshot. iSCSI logoff of the snapshot can fail for multiple reasons  one of them being a process holding a handle to the snapshot volume.  In this case a delete request on the snapshot is received, but because of the iSCSI logoff failure it is insignificant and is ignored and the snapshot is deleted. For such iSCSI logoff failed instances, when the iSCSI initiator tries to connect again to the target, it results in this error.
 

Please ignore this error as it doesn’t impact the functionality of the storage system or the backups process.

For more information, please check the most recent release notes of the Dell EqualLogic Host Integration Tools for Microsoft v4.9:

Occasionally, when the Microsoft Volume shadow Copy Service (VSS) receives a request to delete a VSS snapshot via the EqualLogic VSS Provider, a "Requested target not found" error is displayed in the Group Manager, even though the snapshot has been deleted. You will most likely see this error message after running backups using third party backup software.