PowerPath for Linux : Unable to start PowerPath on Linux system || Getting error "Address for lookup function is missing"


   Article Number:     504371                                   Article Version: 4     Article Type:    Break Fix 




PowerPath for Linux





# systemctl start PowerPath.service   
    PowerPath could not load module emcp   
    Error loading PowerPath kernel modules   
    From messages file --   
    systemd[1]: Starting PowerPath startup script...                                                     
    kernel: emcp: module license 'Proprietary' taints kernel.                                            
    kernel: Disabling lock debugging due to kernel taint                                                 
    kernel: emcp: module verification failed: signature and/or required key missing - tainting kernel    
    kernel: emcp: applying kernel_stack fix up                                                           
    systemd-udevd[604]: specified group 'lp' unknown                                                     
    kernel: Warning:emcp:emcp: Address for lookup function is missing                                    
    PowerPath[2869]: Starting PowerPath: PowerPath could not load module emcp                            
    PowerPath[2869]: Error loading PowerPath kernel modules                                              
    PowerPath[2869]: failed                                                                              
    systemd[1]: Stopping PowerPath startup script...     






The Linux system kernel was tuned by    
    kernel.randomize_va_space = 2   
    kernel.kptr_restrict = 2   
    # cat /proc/sys/kernel/kptr_restrict   
    Above settings/tuning made all the addresses in "/proc/kallsyms" as 0x0000000000 which is not normal and it is not expected by PowerPath startup script. Hence PowerPath service was failing to start.






Installed PowerPath on Linux system and tried to start the PowerPath but it failed.                                                           






Need to revert back the below parameters to the default value. So that "/proc/ kallsyms" start listing proper addresses. And then try to start PowerPath service. It should start.    
    kernel.randomize_va_space =    
    kernel.kptr_restrict =    
    # cat /proc/sys/kernel/kptr_restrict