Convert PowerPath To MPIO on AIX

EMC PowerPath is a proprietary multipathing software from Dell EMC that manages multiple I/O paths between AIX hosts and EMC storage (Symmetrix, VMAX, PowerMax, etc.).

AIX MPIO (Multipath I/O) is IBM’s native multipathing framework, built into the AIX kernel, that provides similar functionality without third-party software.

Both systems handle path failover and load balancing, but PowerPath introduces an additional software layer. Moving to native MPIO simplifies management, improves integration with AIX device drivers, and removes licensing dependencies.

The goal of the PowerPath to MPIO conversion is to:

• Remove EMC PowerPath software (EMCpower.* filesets)
• Reconfigure disks to use AIX’s native MPIO device driver
• Maintain full path redundancy and data integrity
• Standardize multipathing under IBM’s native device management stack
• This process ensures zero data loss, while transitioning to a supported and license-free multipathing configuration.

Use Cases:

• Decommissioning PowerPath licenses
• Standardizing multipathing across heterogeneous storage (IBM, EMC, Hitachi)
• Simplifying OS patching or alt_disk operations
• Migrating to VIOS/NPIV environments where native MPIO is preferred
• Reducing complexity and dependency on vendor-specific drivers

AIX identifies EMC storage disks either as:

• hdiskpowerX → Managed by PowerPath
• hdiskX → Managed by AIX MPIO

The conversion removes hdiskpower devices and rebinds the underlying hdisk devices to use the AIX PCM (Path Control Module) instead of the EMC driver.

There are two main methods:

Direct (In-Place) Conversion:

• Performed when no OS patching or mksysb cloning is needed.
• Stop applications and unmount file systems
• Deactivate PowerPath devices
• Remove EMC PowerPath software (installp -u EMCpower)
• Install EMC MPIO support packages (EMC.Symmetrix.fcp.MPIO.rte)
• Reboot and verify disks are now managed under MPIO (lspv, lsdev -Cc disk)

Safe Conversion via Alternate Disk (alt_disk_copy):

• Preferred in production systems to avoid downtime or rollback risk.
• Create an alternate rootvg using alt_disk_copy
• Perform the PowerPath removal and MPIO installation inside the altinst_rootvg environment (chroot /alt_inst)
• Optionally apply OS patches or updates
• Boot from the alternate disk to activate the MPIO configuration
• This approach allows rollback by booting from the original disk if needed.

Convert PowerPath to MPIO on AIX Alternate Disk (alt_disk_copy):

1. Backup Your System and Copy Software to NIM Server

Mount NFS share /backup and take mksysb backup

# mount nfserver01:/backup  /backup
Create a full system backup including disk layout and volume groups:
# mksysb -ieX /backup/$(hostname)_$(date +%m%d%Y)
Copy Dell EMC installation files to your NFS server (adjust paths & hostnames accordingly):
# cd /software/EMC/
# scp DellEMC.AIX.6.X.X.X* ServerX:/software/EMC/

2. Identify Target Alternate Disk and Prepare for alt_disk_copy
Fix PowerPath root device setup:
# pprootdev fix
List physical volumes in rootvg:
# lspv | grep rootvg

Reduce the disk from rootvg for MPIO convertion

# powermt display dev=hdiskpowerX

# unmirrorvg rootvg hdiskpowerX

# reducevg -df rootvg hdiskpowerX

# chpv -c hdiskpowerX

if altinst_rootvg present then remove alternate rootvg from the server:
# alt_rootvg_op -X altinst_rootvg
Remove PowerPath device from target disk (replace hdiskpowerX and hdiskX accordingly):

# powermt display dev=hdiskpowerX
# powermt remove dev=hdiskpowerX
# rmdev -dl hdiskpowerX
# chdev -l hdiskX -a pv=clear
Verify bootlist is set to normal mode:
# bootlist -om normal

3. Convert PowerPath to Native MPIO
Copy rootvg to alternate disk:
# alt_disk_copy -d hdiskX -P1
Stop PowerPath services inside the alternate rootvg environment:
# chroot /alt_inst/etc/rc.aget stop
Confirm EMC PowerPath package is installed:
# chroot /alt_inst /usr/sbin/lslpp -l | grep EMCpower
Uninstall EMC PowerPath package:
# chroot /alt_inst /usr/sbin/installp -u EMCpower
Remove PowerPath registration file if present:
# chroot /alt_inst /usr/sbin/rm /alt_inst/etc/emcp_registration
Install native MPIO packages (adjust package filenames as needed):
# chroot /alt_inst /usr/sbin/installp -agXYd /tmp/EMC.Symmetrix.aix.rte /tmp/EMC.Symmetrix.fcp.MPIO.rte
Verify installed EMC packages reflect native MPIO:
# chroot /alt_inst /usr/sbin/lslpp -L | grep EMC
Sleep the alternate rootvg disk:
# alt_rootvg_op -S -d hdiskX
Set the boot list
# bootlist -m normal hdixkX

4. Reboot the System (During Maintenance Window)
# shutdown -Fr

5. Verify Conversion from PowerPath to Native MPIO
Check no PowerPath disks (hdiskpower) remain:
# lspv | grep hdiskpower  -- Should show no output
Confirm installed EMC packages reflect MPIO:
# lslpp -al | grep EMC
Verify no PowerPath-defined disks remain:
# lsdev -Cc disk | grep Defined  -- Should be empty or no PowerPath disks
Configure device tunables for MPIO devices (adjust values as necessary):
# for i in $(lsdev -Cc disk | grep -i EMC | awk '{print $1}')

do
chdev -Pl $i -a reserve_policy=no_reserve
chdev -Pl $i -a algorithm=round_robin
chdev -Pl $i -a hcheck_interval=60
done

6. Final Reboot to Apply All Settings
# shutdown -Fr

7. After reboot validate the server:

# oslevel -s  # check os level

# df -g     # check mount point

# lssrc -s <service name>  # check services

If its cluster the 

PowerHA cluster status check:

# lssrc -ls clstrmgrES 
# clRGinfo

GPFS Cluster status check:

# mmgetstate -aL