To check uptime on the hmc.
you must login with ‘hscpe’ user then switch to root user and run ‘uptime’ commands, but this require a PESH Password and you must take it from IBM Engineering Service Support.
The other way which is normal on Linux Distributions when you was on Restricted shel link HMC, you can’t run ‘uptime’ command but you can calculate it within the follwoing way:
login with ‘hscroot’ user, then run the following command:
# cat /proc/uptime
1298394.22 1296466.65
The first number is the number of seconds the HMC system has been up. So you can take that number and convert it to days.
1298394/60 for minutes
21639.9/60 for hours
360.665/24 for days
it will give you : 15.02770833333333 days