How to monitor power supply status using ipmitool on Linux/Solaris?

In linux this worked perfectly for me in current versions of CentOS and Debian

ipmitool sdr type "Power Supply"

I'd recommend you to look at FreeIPMI which is very similar for the systems and how developers claim it is easier in setup and has better portability in comparison with ipmitool. To setup power supply monitoring you can use there Powerman (http://code.google.com/p/powerman/) by adding in powerman.conf

include "/etc/powerman/ipmipower.dev"

device "ipmi0" "ipmipower" "/usr/sbin/ipmipower -h mynodes[0-10] |&"

node "mynodes[0-10]"  "ipmi0" "mynodes[0-10]"

You can look for additional options here (http://www.gnu.org/software/freeipmi/freeipmi-faq.html).