topic NetApp mutipath with Cisco vpc in Ask The Experts

NetApp mutipath with Cisco vpc

NeoLife — Fri, 09 Aug 2019 10:04:25 GMT

Hi ,

anyboday know about netapp(c mode) support run mutipath with ifgrp (lacp) on the Cisco vpc feature?

Each controller ifgrp(lacp),connect to two nexus 5k with vpc, then useing netapp svm run iscsi with mutipath (path on controllerA And B)

Thank you

Re: NetApp mutipath with Cisco vpc

AlexDawson — Fri, 09 Aug 2019 06:18:29 GMT

Hi there! Using LACP for iSCSI connections is supported, but you need to be very careful of ensuring your network is configured in the most reliable way possible. We include it in our Flexpod CVD - https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/UCS_CVDs/flexpod_esxi65design.html#_Toc481589090

ISCSI on Clustered ONTAP requires ALUA and multipathing - access is active/standby, not active/active

Re: NetApp mutipath with Cisco vpc

NeoLife — Fri, 09 Aug 2019 15:52:18 GMT

Hi Alex

Thank you for your reply,

I see the gulde "Ethernet Storage Design Considerations and Best Practices for Clustered Data ONTAP Configurations",

It say ": If you use iSCSI (RFC 3720) in clustered Data ONTAP, there are two methods to achieve path
redundancy. One method is to use IFGRPs to aggregate more than one physical port in
partnership with a Link Aggregation Control Protocol (LACP)–enabled switch. Another method is
to configure hosts to use Microsoft Multipath I/O (MPIO) over multiple distinct physical links.
Both of these methods allow a storage controller and a host to use aggregated bandwidth, and
both can survive the failure of one of the paths from host to storage controller. However, MPIO is
already a requirement for using block storage with clustered Data ONTAP, and the use of MPIO
has the further advantage of no additional required switch configuration or port trunking
configuration. Also, the use of an IFGRP for path management when you use iSCSI is not
supported; again, you should use MPIO with iSCSI. However, the use of an IFGRP as a port for
an iSCSI LIF is supported."

What mean is :the use of an IFGRP for path management when you use iSCSI is not supported."

Thank you so much.

Re: NetApp mutipath with Cisco vpc

AlexDawson — Mon, 26 Aug 2019 06:51:01 GMT

Hi there!

Sorry it has taken a while to get back to you - my understanding is that this means is that LACP should not be used for client connectivity for links running iSCSI sessions to targets, but it is acceptable to use LACP for the connection from the controller (target) to the switching infrastructure that clients connect to.

Hope this helps!