Multi-mode on a single switch isn't so much a netapp thing as a networking thing, but yes - that would cause some serious issues, more than likely.
You can achieve the same thing by doing what we and lots of others do: a multi-mode vif on one switch that is vif'ed together with a multi-mode vif on another switch. The net result is multiple interfaces on a single switch that act as one interface, with multiple interfaces in 'standby' mode on another switch to prevent outages due to switch failure. Works extremely well.
-----Original Message----- From: Jon Hill [mailto:JHill@jennison.com] Sent: Monday, March 10, 2008 6:53 PM To: Glenn Walker; netapp.filer@gmail.com; toasters@mathworks.com Subject: RE: iscsi, mpio of multiple connections with a single head
Yep, that was it. I'm not a networking guy, so I'll probably get some of the syntax wrong, but my understanding is that NTAP requires an Etherchannel between the two NICs being multi-mode VIFfed, which I'm told is only possible when the ports are on the same switch.
-----Original Message----- From: Glenn Walker [mailto:ggwalker@mindspring.com] Sent: Monday, March 10, 2008 6:26 PM To: Jon Hill; netapp.filer@gmail.com; toasters@mathworks.com Subject: RE: iscsi, mpio of multiple connections with a single head
You can't/shouldn't do multi-mode (active/active) VIFs across multiple switches - you can/should do single-mode (active/passive) VIFs across multiple switches. Is this perhaps the issue?
We're quickly moving away from iSCSI HBAs given QLogic's direction to abandon them (so we've heard), and their issues with networking stack on the cards.
Glenn
-----Original Message----- From: Jon Hill [mailto:JHill@jennison.com] Sent: Monday, March 10, 2008 9:43 AM To: Glenn Walker; netapp.filer@gmail.com; toasters@mathworks.com Subject: RE: iscsi, mpio of multiple connections with a single head
We started with VIFs in which each NIC was on a separate switch. After lots of performance issues we talked to NTAP support, who told us we shouldn't be using VIFs on separate switches for iSCSI. I don't remember the details of the case very well, but it seemed our options were to set up the VIF on a single switch, thus introducing a SPOF, or to give each NIC its own IP and rely on MPIO on the client side. We opted for the latter solution and it's worked well for us for about a year now. However, the multi-level VIF you describe sounds like it should work if you have the available NICs.
We put our client NICs on the same subnet too, but we use iSCSI HBAs rather than onboard NICs.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Glenn Walker Sent: Sunday, March 09, 2008 7:27 PM To: netapp.filer@gmail.com; toasters@mathworks.com Subject: RE: iscsi, mpio of multiple connections with a single head
We've been using VIFs exclusively for iSCSI. Not using a VIF could be problematic if the switch were to fail.
Our typical deployment is multi-level vif: 2 active connections as multi-mode vif, 2 passive connections as multi-mode vif, aggregate the 4 links together as single-mode vif.
As for iSCSI on the host, two separate NICs with separate IPs (we put them both on the same network).
Glenn
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of netapp.filer@gmail.com Sent: Sunday, March 09, 2008 11:10 AM To: toasters@mathworks.com Subject: iscsi, mpio of multiple connections with a single head
Hi,
I was wondering what the opinions are regaring setting up iscsi and MPIO.
I have the following setup:
Windows 2003 host, two nics for iSCSI, MS iSCSI initiator, Snapdrive 5.0
Two Network switches
Netapp FAS3020 single head, with 2 nics for iSCSI (should I set this up as a vif?)
How should I set up the IP adresses on the host, should I use a single vif on the filer?
I have searched on the NOW site but there are no guides for this configuration, all config guides only discuss HA (Clustered filers) configurations