I have one lun with 2 paths, and I use MPxIO without loadBallance,.
NOTE: I have v240 server with solaris 10 the latest that connected to the SAN.
Two Question :
1. How I can see which of the paths is the active path?
2. Is the MPxIO can understand which path(from 2 paths to the lun) is the path througth the default controller, and make this path to e the active path?
thanks
A luxadm display /dev/rdsk/cXtYdZs2 will show you path status for that device.
Need to understand what array you are using. For Sun provided arrays, the information is already there or the product release notes will tell you what information you will need for MPXIO.
Arrays from other vendors may need a particular string added into the scsi_vhci.conf file in order for MPXIO to properly talk multi path to them.
HTH
Dom
For that array, Hitachi needs to provide a specific string to enter into the scsi_vhci.conf file, telling MPXIO how to deal with that array.
It should be in the array Release Notes or Install Guide, along with any particular levels of microcode and array port settings needed. The scsi_vhci.conf entry will provide the string that a host scsi inquiry will return, along with the specific scsi options that the OS will need to talk to the array using multi pathing. Once those changes are done usually a boot -r will be required.
Until that is done, Solaris will see both paths to the array as seperate and distinct arrays, so no multi pathing will be done.
HTH
Dom
If they are both showing Online Primary then MPXIO thinks thats what they are.
If load balanced under the default method it will round robin IOs, if no load balance then it will pick one when an IO is sent and use it.
Unless a specific method was provided to pick an active path thats how it works. You really need to get the proper set up information from Hitachi for this array.
You can't tell for certain, unless you disable a path.
Your questions are circling back to what you have already asked before, if you really need this much help I'd suggest you open service cases with your two vendors, Hitachi for getting the array to work with MPXIO, then Sun for deeper questions on MPXIO.
Good luck.
thank u very much, this is ecsactly what I did.
I consolting SUN & HDS, and I think that the problem solved -
the parameter "load-balance" most be "Round robin" and that it!!!!
mpxio execute the I\O to the default controller of the lun, and then only if the path to the default controller disconnected, mpxio execute the I\O from the second path.
thanks
There are two types of arrays. Asymmetric and symmetric.
Asymmetric arrays, for the most part, require special code in the multipathing driver in order to work correctly. Examples of these arrays are Sun T3, 6540, Clariion. I believe the AMS500 is an asymmetric array.
If the AMS500 doesn't support the T10ALUA spec then the multipath driver must be changed to support it. In that case you wouldn't need to modify any conf files with the exception of the desired mode. If HDS told you to add the AMS500 as a symmetric array when it's really asymmetric - They should be able to tell you - then this won't work at all.
