Symptoms
AIX Power 7 running PowerPath 6.0.0 booting from Unity 400F .the customer was unable to successfully upgrade the image on the SAN. but could do the upgrade to the internal disk. PowerPath was uninstalled before the upgrade on the SAN disks.The upgrade from AIX v6.1 to v7.1 starts to write to hdiskpower0. The OS doesn't know about the hdiskpower disks the upgrade fails.The error received is "all hdisks have the same physical volume ID" comes up during the upgrade or when the O.S. it is about to start.As a result you can't mount Filesystems,or base information.Powerpath is presenting a disk that AIX can't deal with ((hdiskpower0)).Individual hdisks are presented to the AIX operating system.
Cause
Trying to create a copy of boot from San using PowerPath.
Resolution
Use alt_disk_copy to copy the rootvg from the SAN to local AIX diskUpgrade AIX on the local diskUse alt_disk_copy to copy the upgraded rootvg from local AIX disk back to SAN.Boot from SAN using Powerpath after confirming that pprootdev on has been run...One point to note is that if current SAN boot disk is managed by PowerPath, please update the bootlist manually after performing alt_disk_copy since the bootlist only allows hdisk entries not hdiskpower ones.
