AIX

Sorry guys but let me start off by saying I am an AIX noob! I am running AIX 6.1 and recently purchased two iSCSI TOE cards. The plan is to connect these two cards to a Dell EqualLogic SAN and that has two volumes configured for logs and data.

The point of the two cards is to do load balancing and fail over if one card does, obviously I am interested in making this reliable and always available.


What I have done so far is:

Configured the ics0 and ics1 to have
IP addresses on the iSCSI network with the SAN
discovery policy of file
Edited the /etc/iscsi/targetshw# to include the paths to both volumes that I have configured

Now, when I do lspv, I see four new hdisks, because each card has connected to each volume. So obviously I have duplicate connections.

What I want to do is have these two cards load balance the connection and failover if a card dies and that's where I am stuck. I have read a little on MPIO but not having much luck with iSCSI TOE.

Can anyone add any configuration advice, it would be much appreciated!!

Not my forte, but did you read this and attachments yet? IBM Techdocs White Paper: Disk Path Design for AIX including SAN Zoning

This looks like a good read, to: http://documentation.commvault.com/h..._practices.htm

This seems to take it step by step: http://pic.dhe.ibm.com/infocenter/ai...%2Fdevmpio.htm

Thanks, I skimmed the article and it kind of assured me of something I read in an article Dell published. I will copy and paste it below, the article was from 2009 so I was hoping that maybe they had resolved this by now. I went ahead and opened a case with Dell to see what they will suggest or if they will confirm it is not supported.

MPIO is not supported between the IBM HBA cards and EqualLogic PS Series storage
arrays. If you have multiple HBA ports, you should split your volumes among your ports,

but be careful to only connect once to any volume.

Of course this is not free, maybe created to work around the IBM thing you mentioned:
Alternate Data Paths (GridStor)

This says you need a switch, which might be in what you describe: Help - AIX 7.1 Information Center

What does your system say to these tests?
http://pic.dhe.ibm.com/infocenter/ai...suppmpdevs.htm

When I do a

lsdev -Cc disk

My hdisks to the EqualLogic show up as "Other iSCSI Disk Drive" so I assume really my issue is because it is truely not supported. I did read this in one of the articles you linked from IBM.

Devices not supported by the AIX disk PCMs or tape PCMs require the device vendor to provide attributes predefined in the ODM, a PCM, and any other supporting code necessary to recognize the device as MPIO-capable.

When I run lsattr -El hdisk# for the disk of the SAN it does not show the PCM or algorithm settings.

Still waiting for the response from Dell, I did not see any downloads on their site for ODM. I will look at the possible workaround you posted.

Maybe you need a newer AIX? "Beginning with AIX 5L™ Version 5.2 with the 5200-04 Recommended Maintenance package, iSCSI disk devices are supported as MPIO devices."

My understanding is it's because I am using HBA cards. Otherwise if I was using the iSCSI software initiator and NIC ports it would work.


Just spoke to Dell and they linked me the same MPIO article on IBM's site. We came to the same conclusion that it seems like the AIX is missing some sort of software or driver to make it properly recognize the EQL.

Also my OS level is 6.1.0.0