> The problem is this: the 3par commands are continuous and only stop when you press the 'enter' key.

Most if not all of the stat commands have the "-iter <x>" option, which limits the output to <x> iterations. You can combine that with the "-d <y>" option to average the output over <y> seconds.

So you could change your command to be...

"ssh -l gmon 3par-S400 statvv -ni -d 30 -iter 1"

and just call that each time you want an additional set of stats.

BTW, depending upon the info you're trying to graph, statvlun, or "statvlun -vvsum" might be more appropriate output.