Uninstalling powerpath when your rootvg resides on a SAN LUN, is not so easy, because you can’t install concurrently the MPIO disk driver fileset, with the one you’re using with powerpath ! And you won’t be able to uninstall the latter (in order to install MPIO support for your disks), unless you wanna play with the ODM.

But first things first :

Unconfigure powerpath

PS : on some older versions (like 5.3 SP1), the argument « all » is not valid, you will need to specify each volume
specifically.
If you encounter this message (because you have open VG’s on the disks), don’t worry, the unmanage option will be active for the next reboot:

If not done yet, unmanage your rootvg hdisk and reboot to get rid of all powerpath managed stuff:

Uninstall powerpath

Now we can uninstall powerpath:

Install MPIO… Failure

As I said, you can’t have EMC.Symmetrix.fcp.rte and EMC.Symmetrix.fcp.MPIO.rte together on the same system, as you can see below when I try  to install it:

–> When you uninstall powerpath, the device driver is still in use for your disks. But you can’t install the latter when the former is still present . How to manage that ?

Clean up a bit

I like to have a clean and simple configuration  before starting this kind of operation : I delete all hdisks (before this step you need to umount FS and varyoff vgs , of course) :

The problem is that the rootvg is in use, and you cannot delete it , hence you cannot uninstall the symmetrix.fcp.rte package.

So we have to find another way, which is modifying the rootvg’s hdisk’s ODM entry:

ODM modification

First we need to backup the definition in a text file, then backup the CuDv base :

Let’s edit the text file in order to change the disk’s definition to the standard no-driver « MPIO Other FC SCSI Disk Drive » definition (if you don’t have perl installed, just edit manually the file, changing the line PdDvLn = [your disk driver] by PdDvLn = « disk/fcp/mpioosdisk ») :

Now we erase the disk’s definition in its ODM entry which is still in my case « EMC Symmetrix FCP VRAID » :

We load the modified ODM entry into the ODM :

Verification :

Ok so the disk is no longer recognized as a symmetrix disk, we should be able to uninstall the driver !

Uninstall FCP driver

In my case I had an extra problem concerning this step :

Actually my /dev/ipldevice was missing, I had to recreate it :

then I re-ran the uninstallation :

MPIO installation (again)

OK so now we should be able to install the MPIO supported driver :

Be sure to run bosboot command and verify your bootlist, before rebooting  just in case…

Now we can reboot the server and check with lspath and lspv that our disks are now managed by MPIO!