[Users] CentOS 6 and multiple ISCSI interfaces/multipath

[Dan Yasny]

Currently vdsm doesn't use the IFACE param at all, it simply tries to
discover the target by IP, letting the kernel do the routing. So for
multiple paths, you need to split the host NICs into different subnets, set
up the portals on those subnets, and discover/login on those separate IPs
from different subnets. The host kernel will take care of which NIC to use
for which iSCSI session


On Tue, Jun 18, 2013 at 4:25 AM, Gary Lloyd <g.lloyd at keele.ac.uk> wrote:

>
> Dan Yasny <dyasny at ...> writes:
> >
> >
> > This is an old issue with EQL, best practice is to have different iSCSI
> paths on different subnets or VLANs, and to login to every iSCSI portal
> when
> you create the storage domain.
> > Alternatively, you can use bonds of course
> >
> >
> > On Thu, Jun 13, 2013 at 4:41 PM, Martin Goldstone <m.j.goldstone-
> gMJiioYAC8g at public.gmane.org.uk> wrote:
> > Hi all,
> > I've recently started looking at oVirt to provide the next iteration of
> our virtualization infrastructure, as we have recently acquired some ISCSI
> storage. Up to now, we've been using KVM managed by libvirt/virt-manager
> locally on each of our hosts, using direct attached storage, which was
> obviously less than ideal.
> >
> >
> > In setting it all up, I've hit a bit of a snag. We've got 4 GbE network
> interfaces on our pilot host (running vdsm on CentOS 6.4) which are
> connected to our storage arrays (equallogic). I've created 4 interfaces
> with
> iscsiadm for these and bound them, but when setting up the discs in oVirt,
> I've not seen a way of telling it which interfaces to use. The node makes
> the connection to the target successfully, but it seems its only connecting
> via the "default" iscsi interface, and not making a connection via each
> interface that I've defined. Obviously this means I can't use multipath,
> and
> being only GbE interfaces it means I'm not getting the performance I
> should.
> >
> >
> > I've done some searching via Google, but I've not really found any thing
> that helps. Perhaps I've missed something, but can anyone give me any
> pointers for getting this to work across multiple interfaces?
> >
> >
> > Thanks?
> >
> > Martin
> > _______________________________________________
> > Users mailing listUsers-
> dEQiMlfYlSzYtjvyW6yDsg at public.gmane.orghttp://
> lists.ovirt.org/mailman/listin
> fo/users
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users at ...
> > http://lists.ovirt.org/mailman/listinfo/users
> >
>
> Hi Dan
>
> I work with Martin.
>
> The problem we are having seems to be with regards to how ovirt/vdsm
> manages
> iscsi sessions and not how our server is connected. I have manually tested
> iscsiadm on the same machine(Centos 6.4) and we are indeed getting multiple
> sessions from 2 ifaces with mpio working via dm-multipath, etc.
>
> vdsm however does not appear to be logging into the targets using the
> ifaces
> we use in iscsiadm, I have tried adding this to /etc/vdsm/vdsm.conf, but it
> makes little difference:
>
> [irs]
> iscsi_default_ifaces = eth2,eth3
>
> Thanks
>
> Gary
>
>
>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/users/attachments/20130618/2ab6d6b8/attachment-0001.html>