https://community.netapp.com/t5/ONTAP-Discussions/MPIO-is-loosing-paths/m-p/102190#M20726 <P>Hi,</P><P>&nbsp;</P><P>we are currently facing a strange problem. We shifted to a new Fas8040 MetroCluster in 7-Mode.</P><P>Most of our systems are running virtualized on Microsoft HyperV in redundant fibre-channel environment (2 independent fabrics).</P><P>On our Windows Server 2012 R2 HyperV-Hosts we have the Data Ontap DSM 4.1 installed. The igroups have ALUA enabled.</P><P>&nbsp;</P><P>The MPIO usually shows 4 paths, where 2 paths are "unoptimezed" and "disabled". From time to time ... I promise without any changes from our side and without any FC-Switch / Port Problems one or two physical HyperV hosts loose their optimized paths to the LUN and therefore take the vtic path.</P><P>&nbsp;</P><P>What we have to do to change this behavior is quite simple ... Open device manager, right click, recsan for new hardware and ... woohooo ... all 4 paths are available again and traffic runs over the "good" paths again.</P><P>Any ideas what's going on???</P><P>&nbsp;</P><P>What is the NetApp DSM "Enable Path Verify" Option for? It's disabled by default. Could this solve my problems?</P> Thu, 05 Jun 2025 04:47:31 GMT JMeisel 2025-06-05T04:47:31Z https://community.netapp.com/t5/ONTAP-Discussions/MPIO-is-loosing-paths/m-p/102190#M20726 <P>Hi,</P><P>&nbsp;</P><P>we are currently facing a strange problem. We shifted to a new Fas8040 MetroCluster in 7-Mode.</P><P>Most of our systems are running virtualized on Microsoft HyperV in redundant fibre-channel environment (2 independent fabrics).</P><P>On our Windows Server 2012 R2 HyperV-Hosts we have the Data Ontap DSM 4.1 installed. The igroups have ALUA enabled.</P><P>&nbsp;</P><P>The MPIO usually shows 4 paths, where 2 paths are "unoptimezed" and "disabled". From time to time ... I promise without any changes from our side and without any FC-Switch / Port Problems one or two physical HyperV hosts loose their optimized paths to the LUN and therefore take the vtic path.</P><P>&nbsp;</P><P>What we have to do to change this behavior is quite simple ... Open device manager, right click, recsan for new hardware and ... woohooo ... all 4 paths are available again and traffic runs over the "good" paths again.</P><P>Any ideas what's going on???</P><P>&nbsp;</P><P>What is the NetApp DSM "Enable Path Verify" Option for? It's disabled by default. Could this solve my problems?</P> Thu, 05 Jun 2025 04:47:31 GMT https://community.netapp.com/t5/ONTAP-Discussions/MPIO-is-loosing-paths/m-p/102190#M20726 JMeisel 2025-06-05T04:47:31Z