Checking opensolaris physical memory inside a zone

Joyent uses OpenSolaris zones for its accelerators. At some point I needed to verify the physical memory size of one of these zones but was unable to use the webmin tool that Joyent provides. This seemingly simple operation was actually pretty tricky to figure out. Here are the steps I followed:

 
$ sudo rcapadm -E
                                      state: enabled
           memory cap enforcement threshold: 0%
                    process scan rate (sec): 15
                 reconfiguration rate (sec): 60
                          report rate (sec): 5
                    RSS sampling rate (sec): 5
$ rcapstat -z 1 1
    id zone            nproc    vm   rss   cap    at avgat    pg avgpg
    46 foo            -    0K    0K 2048M    0K    0K    0K    0K
$ sudo rcapadm -D
                                      state: disabled
           memory cap enforcement threshold: 0%
                    process scan rate (sec): 15
                 reconfiguration rate (sec): 60
                          report rate (sec): 5
                    RSS sampling rate (sec): 5
$ 

rcapadm seems to be a resource management tool. I’m not sure if there’s an impact to leaving it running, but I disabled it just in case.