Home > Storage > Data Storage Essentials > Storage Admin > Fabric Notifications with Dell PowerMax > Best Practices for Fabric Notifications with Multi-Pathing Software and Operating Systems
On the surface, multi-pathing software such as MPIO and Dell PowerPath would seem to address the SAN issues detailed in this whitepaper. Unfortunately, multi-pathing software struggles with these events due to their intermittent nature. When there is an issue, multi-pathing software will often end up sending data down an impaired path and into the fabric resulting in congestion or worse.
MPIO and PowerPath both support Fabric Notifications. Fabric Notification support allows multi-pathing software to react more quickly when there is a problem in the SAN. That’s because the switch has more visibility to the causes of link integrity and network congestion than the end-device, thus enabling the switch to declare an event sooner and send notifications to all end-devices within the zone.
Operating system and HBA support are required to enable this since the Fabric Notifications must be passed from the SAN to the HBA to the operating system and finally to the multi-pathing software. Operating system support for Fabric Notifications was first introduced in 2020 with Red Hat Linux 8.3 and IBM AIX 7.2TL5. SUSE Linux support debuted with Version 15 SP4. VMWare ESXi 8.0 currently only supports Fabric Notification logging. VMWare support for MPIO and PowerPath is targeted for a future release of ESXi. Please refer to the Fabric Perf Impact Notification (FPIN) Simple Support Matrix within the PowerMax/VMAX All Flash/VMAX3 Features Simple Support Matrix for more information and for Dell supported configurations.
Finally, please note that as of the publication of this whitepaper, MPIO and PowerPath do not currently support link integrity notifications originating from NVMe-FC SANs. This capability requires operating system support which has been promised by several vendors. However, congestion notifications are supported with NVMe-FC. Please refer to the operating system release notes for more information and updates.