On Thu, Jun 30, 2016 at 02:49:37PM -0700, chandler s. wrote: > Dear group, > > We have an iSCSI device which has two controllers, and each controller has > two host ports. We also have two networks available. Thus: > - controller1-port1 is plugged into network1 and has ip1-1, > - controller1-port2 is plugged into network2 and has ip2-1, > - controller2-port1 is plugged into network1 and has ip1-2, > - controller2-port2 is plugged into network2 and has ip2-2. > > The initiator also has two NICs, eth1 and eth2 connected to each network, > respectively, and has ip1-3 and ip2-3. Suppose we only have one volume > exported on the iSCSI device. This volume now shows up as four different > devices on the initiator (which is running RHEL5). I can see in > /dev/disks/by-name that there is a link to the devices using each of the IP > addresses (ip1-1, ip2-1, ip1-2, and ip2-2). Logically I would want to only > mount one of these devices at a time, in order to prevent data corruption. > The other devices are present in case a controller or network goes down. > > I was wondering how i could ensure, for example, if i have the device > mounted using network1, that eth1 would be used for the data transfer, as > opposed to eth2 which would require additional hops?
It sounds like you ran a single discovery command to the target, which reported back all 4 of it's IP addresses. So 'iscsiadm -m node -P1' would report 1 target, with 4 portals, all with iface "default"? That's certainly the easiest configuration, as it's going to let the IP routing tables determine which interface is used for each connection. It probably does what you want, except that if a link goes down the redundant connections will just get re-routed. The way to manually control this is using iface records. You need to create an iface record for each NIC, binding them by ethernet MAC address. You could then run discovery over each of the ifaces, possibly ending up with 8 records and wanting to delete the ones you don't want on each iface. I don't know if it's possible to set and iface binding on existing records, after a "default" discovery for instance, I'd have to check. As for accessing the SCSI devices, I'd highly recommend looking at DM multipath and doing all access through the mpath map device. - Chris -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
