I have couple of basic questions on Powerpath installation and operation on AIX
1) Are there any extra benefits of using Powerpath for rootvg instead of MPIO ? What does PowerPath offer that MPIO doesn't ?
2) If we implement PowerPath later after rootvg has been using NPIV under MPIO control, are there any issues ?
We had a LPAR booting off EMC using NPIV under MPIO, then boot device has 4 paths configured from VMAX array. And then Powerpath and ODM sets were installed on LPAR; boot and data devices are brought under Powerpath control. This way is not in the install guide, not sure if there are any concerns doing this.
Thanks , I appreciate any feedback.
Hi Sanquest - see the below white paper for comparison on PP and MPIO:
PowerPath is constantly updating and optimized its code for EMC arrays (including XtremIO) and the latest OS releases.
There is a new multipathing algorithm from AiX that is based on round-robin called shortest queue. We've been able to demonstrate PowerPath performance advantages over AiX
I'm not sure I understand question #2, perhaps others on the community can weigh in.
PowerPath Product Manager
Thanks Bob for the white paper. I think that 'd help
May be I will rephrase my second question
The second question is regarding how I bring the boot devices under powerpath control.
This is the order we followed
EMC devices are provisioned to LPAR with 4 paths, 4 hdisks are configured for each device, The device is controlled under native MPIO
We got LPAR booting of one VMAX device
Powerpath and the ODM fileset set are installed on the LPAR
Ran powermt config and brought the boot device and other devices under powerpath
Are there any issues doing the above process?
In the Install Guide, it is mentioned in this order to start with only a single path to storage system initially, install AIX on the device; and install powerpath and ODM; then add new paths and configure hdisks for each path; run powermt config and pprootdev on.
What I am asking here is,having started with mutilple paths for the boot device instead of one path before powerpath is installed, would there be any issues ??
One issue we encountered by far is we are not able to add all the hdisk paths to bootlist, it only added two out of four paths to AIX bootlist. I dont know if this is because of the install procedure we did.