AIX

Are both controllers on the same cable, or is the SAN a two port device?

There is actually a switch between the two, I failed to mention that before. So each controller has it's own cable. An ethernet cable goes from each HBA to two different switches, and then the SAN has four connections total between the two switches. So I want to be able to lose a card or a switch and still be functional.

---------- Post updated at 11:18 AM ---------- Previous update was at 11:13 AM ----------

An MPIO other iSCSI disk is a subset of other iSCSI disks. A device is supported as an MPIO other iSCSI disk only if there is no vendor-provided ODM predefined attributes and the device has been certified to operate with the AIX PCM. Certification does not guarantee that all device capabilities are supported when the device is configured as an MPIO other iSCSI disk.

To determine which devices are supported as MPIO other iSCSI disks, run the following script: odmget -quniquetype=disk/iscsi/mpioosdisk PdAt | grep deflt | cut -d'"' -f2
The script output displays a list of inquiry data that contains the device vendor and model.


When I ran this command I got an error

0518-507 odmget: Could not retrieve object for PdAt, ODM error number 5904

Is this PS series SAN?

Do you have an EquaLogic support login, to look for odm/pcm files to support MPIO ?

Yes, PS4100

I was wondering if there is an ethernet load balancing and failover solution for this, since it is partially dual/quad ethernet. Are there actually two scsi cables or other controller paths in the SAN that need to be balanced ?

I found this, looks promising, bottom of page 10: http://www.qlogic.com/Resources/Docu...EqualLogic.pdf

I do have the EqualLogic login and looked but found nothing useful there for AIX.

The SAN is completely using iSCSI, has two separate controllers completely that are for redundancy in case of hardware failure. That does not have to be balanced because it's only used if the other controller isn't active. It has two ports on each controller that it will load balance or failover as well.

Are the two controllers on different cables?
If so, are the disks dual-port scsi, not mirrors?
Could it load balance the controllers remotely? (I guess if the primary controller failed, it could not pass traffic to the other.) In other words, would network load balancing and failover be sufficient? (Not sure how good AIX is at network load balancing!)

It seems Veritas can take over this function, which they call DMP. They still need the ODM set up right, but turn off MPIO!

Another nice article. I think the key is the ODM setup.

http://aix4admins.blogspot.com/2011/...aix-at-no.html

EquaLogic AIX iSCSI manual: http://attachments.wetpaintserv.us/u...Dy4TkEkA320298