Powerpath issue on HP Unix

Recent Issue:

Server was ignited earlier using OS image of one of the similar hardware model.
We had some issues on performance and found Powerpath issue. Removed the powerpath and installed it again, It required kernel rebuild and started system reboot. But system was not able to boot. Below is the error faced.


ERROR: phy_unit_init: Could not open file: /tmp/ign_configure/hw.info: No
such file or directory (errno = 2)
ERROR: read_hw_info failed

The configuration process has incurred an error, would you like
to push a shell for debugging purposes? (y/[n]):

Solution:
When powerpath software was uninstalled, it restored the pre-ignited image script to the startup files. This caused the server boot to fail checking for ignited configuration files in /tmp directory.

The backup files are saved during the post-installation when the server is ignited. In general the files should not be altered but PP package removal seems to behave differently.
The start scripts which were sourcing for ignited files were removed, rescanned the hardware, and the server was fully tested without PowerPath 5.1 installed.

After validation, we installed Power Path 5.1

learn:/sbin/rc2.d>swlist | grep -i emc
EMCpower HP.5.1.SP2_b113 PowerPath

After installation, the power path does not work as expected and behave the same way as the earlier version

learn:/sbin/rc2.d>sh S999emcp start
Unexpected error occured.
emcpmgr: internal library error (0xebad002)
Error: unable to update device configuration file(s)
No migrations found.

learn:/sbin/rc2.d>powermt display dev=all
Initialization error.

After numbers of attempts with remove/install PP, We finally found the main problem. It is actually a bug with PP and from versions like 4.x it is still there. What happened was that the entry in the /etc/inittab file for PP initialization which is running BEFORE the /sbin/init.d/emcp script and loads kernel modules to the host was missing on the host. /etc/inittab should have been updated during installation, but because that bug, it was not and PP kernel modules could not load at boot.

The entry below has been added to the /etc/inittab file and after reboot PPworked fine.
pwr::sysinit:/sbin/emcpstartup /dev/console 2>&1 # PowerPath

We should have noticed that earlier, but found it at the end.

You can find the solution on Powerlink article emc93018.