On Tue, Feb 22, 2011 at 6:47 PM, Jason Gunthorpe <[email protected]> wrote: > On Sun, Feb 20, 2011 at 02:33:01PM +0100, Bart Van Assche wrote: >> A convenient way to provide high availability when using fail-over >> between two IPv4 iSCSI servers is to configure the HA software such >> that a secondary IPv4 address is only assigned to the active server. >> I'd like to build a HA SRP setup using a similar approach. This leads >> me to the following question: does there exist an equivalent of >> virtual IP addresses for IB ? As far as I can see in the IBTA specs a >> subnet manager can assign a secondary GID to an IB HCA port >> dynamically. >> >> Does any of the existing IB switches support this ? If so, how does >> communication between HA software and IB switch happen ? >> >> Does OpenSM support assigning secondary GIDs to a HCA port ? > > Unfortunately this is an area where the IB spec has quite a lot of > richness but AFAIK it doesn't get used too much.. > > I don't think IP like GID migration is appropriate for IB, GUIDs > should be fabric unique. I'd suggest you should look at supporting > multiple GIDs registered for a single service ID and use those GIDs as > the set of fail over end ports. Supporting setting up APM as well > would be great. ;) > > In IB if a port falls off the subnet the SM will not return paths for > it, so you can tell quickly that a service record is dead without > incuring a timeout. Essentially the SM takes the roll of the HA > software you see in IP land.
Hi Jason, The reason I started looking for an alternative for setting up multipath between one SRP initiator and redundant SRP targets is because such a configuration is a little awkward to set up. I am aware that GUIDs must be fabric unique. In case a subnet manager would assign a secondary GID to a HCA port, I see it as the responsibility of the operator who configures that secondary GID in the subnet manager that it is fabric unique and as the responsibility of the subnet manager to make sure that that GID is assigned to at most one HCA port at any time. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
