On Wednesday, February 8, 2017 at 1:56:07 AM UTC-8, Satyajit Deshmukh wrote: > > Hello, > > We have a setup, where we are using the iSCSI redirect functionality, > where we connect to a highly available persistent address, and get > redirected to a different address/portal. > Our setup allows modifying the persistent IP address of the iSCSI targets, > amongst active I/O to the iSCSI sessions to the redirected > addresses/portals. > The requirement is to ensure non-disruptive I/O when any portal crashes. > (persistent address/portal is assumed to be still available) > > Consider a scenario where sessions are redirected to different > addresses/portals and now the persistent portal address is modified on the > target. > > Without this patch: > When the redirected portal crashes, iscsid would tries to recover the > session by reconnecting to the incorrect/stale in-memory 'failback_saddr' > portal. > Since, this IP is modified on the fly, iscsid tries reconnecting to a > wrong portal. > > With the patch: > Patch notifiies iscsid about the change in the persistent address of all > the sessions via the iscsiadm utility. > All in-memory session structures' failback addresses are updated with the > new persistent address. > > We have unit-tested the patch in our setup and we can see sessions > recovering amongst current portal failures. > Usage: > > iscsiadm -m session -n updated_persistent_ip_address -v 192.168.5.5 > > Would be great if someone can review the attached patch. Any > feedback/suggestions/questions greatly appreciated. > > Thanks, > Satyajit >
I haven't seen a reply from Chris yet (is there one I missed?), but I can say I don't like this much. If I understand correctly, you're trying to handle the case where your persisent target address/port changes. Is that correct? This is precisely the kind of thing that target directory services are meant to deal with. Instead of having a hard-coded address, you look it up. Also, iSNS (the target directory service) can even send asynchronous notification of changes. Also, just as a piratical matter, changing the persistent address of Nodes in use seems like changing a tire on a running car. 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.
