[Users] iSCSI multipath with EqualLogic SAN

[Chris Noffsinger]

We have 2 Equallogic PS4100s.  And someone more knowledgeable may prove me
wrong here but,

Multipathd is not my most favorite thing to configure, but you can
configure your nodes to use the other paths using the command line on the
Centos nodes.

Yeah Dell will tell you that they want you to use their software (like the
mem plugin in Vmware) but the Linux OS will see the other paths and treat
it like any other SAN, you are just going to have to configure them to use
them.   The link sent earlier in the thread is the official guide to doing
that.

https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/pdf/DM_Multipath/Red_Hat_Enterprise_Linux-6-DM_Multipath-en-US.pdf


Here is another Doc I used that is for Rhel5 but I beleive the multipath
commands are the same:

http://www.equallogic.com/WorkArea/downloadasset.aspx?id=8727


On Thu, Feb 21, 2013 at 1:09 PM, Jonathan Horne <jhorne at skopos.us> wrote:

> Ive discussed this at length with dell's EQ support team, and on a regular
> system that's connected in to an equallogic san, all the iscsi ports would
> be on the same subnet.  The kicker is, dell really wants you to use their
> specialized driver/iscsiinitiator to access (known as their HIT kit...host
> integration tools), and the HIT kit handles establishing all the multiple
> sessions into the EQ SAN.
>
> Unfortunately, equallogic  doesnt support RHEV (and thus ovirt), and ovirt
> does not seem to execute the commands the HIT driver would want to
> intitiate multiple connections.
>
> Dell says that the use of bonding for iscsi just begs for tcp retransmits.
>  since bonding is the only method of failover I see for now, were using
> anyway against their recommendations (so far zero retransmits, but were not
> running our systems hard yet).
>
> Cheers,
> Jonathan
>
> -----Original Message-----
> From: users-bounces at ovirt.org [mailto:users-bounces at ovirt.org] On Behalf
> Of Sven Knohsalla
> Sent: Thursday, February 21, 2013 8:55 AM
> To: Baptiste AGASSE
> Cc: users at ovirt.org
> Subject: Re: [Users] iSCSI multipath with EqualLogic SAN
>
> Hi Baptiste,
>
> usually a SAN doesn't support bonding (see post of Nicolas) of its
> interfaces, so you have to use multipathing technology.
>
> You have to separate all nics in different subnets so multipath can work.
> Command multipath -ll with show the connected paths.
>
> If you "merge" all paths in one subnet you will have the result/behavior
> you just posted.
>
> So this is less oVirt related, more network specific.
> We have a running iSCSI config with 4 networks and oVirt runs well.
>
> Maybe the following link will help you here:
>
> https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/pdf/DM_Multipath/Red_Hat_Enterprise_Linux-6-DM_Multipath-en-US.pdf
>
> Cheers,
> Sven.
>
> -----Ursprüngliche Nachricht-----
> Von: users-bounces at ovirt.org [mailto:users-bounces at ovirt.org] Im Auftrag
> von Nicolas Ecarnot
> Gesendet: Donnerstag, 21. Februar 2013 15:48
> An: users at ovirt.org
> Betreff: Re: [Users] iSCSI multipath with EqualLogic SAN
>
> Le 21/02/2013 11:30, Baptiste AGASSE a écrit :
> > Hi all,
> >
> > I'm testing ovirt 3.1 on centos boxes. I setup ovirt management node
> > and 4 vdsm hosts. vdsm hosts have 2 nics on the SAN subnet. When i
> > create a iscsi storage domain, it use only one of the two nics on the
> > SAN network (showed with iscsiadm -m session on vdsm nodes). Does
> > ovirt support multiples nics on the same subnet for iscsi SAN
> > connection ?
>
> I don't know if this is the best setup, but this is exaclty what I did
> (iSCSI with an Equllogic SAN) : I bonded 4 interfaces of the iSCSI subnet,
> and it's working fine so far...
>
> --
> Nicolas Ecarnot
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
> ________________________________
> This is a PRIVATE message. If you are not the intended recipient, please
> delete without copying and kindly advise us by e-mail of the mistake in
> delivery. NOTE: Regardless of content, this e-mail shall not operate to
> bind SKOPOS to any order or other contract unless pursuant to explicit
> written agreement or government initiative expressly permitting the use of
> e-mail for such purpose.
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>



-- 
Chris Noffsinger
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/users/attachments/20130221/63e4d1ad/attachment-0001.html>