Here is a copy and paste from an email I sent to others currently working on our issue. I'm trying to clarify how iscsiadm works with the ifaces:
=================START PASTE Don, On July 22, 2008 you had written to the open-iscsi mailing list. Here is a link to that post: http://groups.google.com/group/open-iscsi/msg/f94fbc5f66202e61? In that post, you mentioned using the following: Portal: 172.23.10.242 iface.eth0: 172.23.49.170 iface.eth1: 172.23.49.171 What I'm trying to find out is a definite answer on how the `iscsiadm -m iface` works --specifically with respect to linux routing. ITEC would like to use the iface to allow for multiple sessions to connect to the same volume. However, what we're having trouble with is understanding what happens from an iSCSI perspective when we use the ifaces. In addition, we'd like to help Oracle understand this as well (if they in fact have any doubts). Do you happen to have any connections with any of the open-iscsi developers? If so, would you be able to pose a question to them on our behalf? 1) iface networks - with regards to `iscsiadm -m iface` with software iSCSI initiators, was the design meant to work with two interfaces on the same network segment or with the interfaces being on different segments? In the scenario where they are on the same network segment, standard linux routing would send any outbound traffic out whichever interface appears first in the list of routes. In our situation eth2 and eth3 being dedicated to ifaces eth2 and eth3 respectively. When sessions are created out both ifaces and logged in, whenever I/O goes to eth2 (if standard linux routing is involved) all traffic would go out eth2 (since it happens to be the first that appears in my `netstat -rn` list). However, when iface eth3 is used for I/O, (again, if standard linux routing is involved) wouldn't all outbound I/O attempt to be routed down eth2? I know that, during an earlier email I sent, you already said that the initiator would take care of it but ITEC and Oracle are both trying to understand how. By the way, I'm still working on getting a 5.3 system running for testing purposes. =================END PASTE Thanks, Joe -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Tuesday, July 07, 2009 5:05 AM To: Hoot, Joseph; [email protected] Subject: RE: Dell Linux Wiki - open-iscsi, iface, and mpio > -----Original Message----- > From: [email protected] [mailto:linux- > [email protected]] On Behalf Of Hoot, Joseph > Sent: Tuesday, July 07, 2009 5:42 AM > To: linux-poweredge-Lists > Subject: Dell Linux Wiki - open-iscsi, iface, and mpio > > I'm trying to find out who wrote the following wiki article: > > http://linux.dell.com/wiki/index.php/Products/HA/DellRedHatHALinuxClust > e > r/Storage/EqualLogic_PS- > Series/Cluster_Nodes#Configure_iSCSI_Initiators_ > for_Multipath > > I have been working with Dell and Oracle representatives with regards > to > getting multiple sessions to an iSCSI EqualLogic volume working behind > dm-multipath. We're trying to understand how the open-iscsi > implementation works under the hood. This article seems to sum up what > we've done, but I'd like to see if any open-iscsi developers were > involved. > > Thanks, > Joe Joe - I am not too sure on the author but we have a few iSCSI guys on this list. Specific questions would help. For starts each EQL volume is associated with an iqn and hence you can build multiple sessions by creating multiple initiator portals at the host side. Each of them would login to the EQL volume portal through iface bindings - Ifaces(upstream code) could be created based on the following - a) IQN b) MAC address c) interface name d) transport type -Shyam Iyer _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
