prstat and ps command not working

hello,

i am using solaris 10 , with configured zones

since last two days i am facing the problem

when i execute the prstat , ps pfiles ,w it not responding even its
not terminated by any break keys

for example

i tried to executed , prstat its stop like below o/p

$prstat
Please wait...

we are using sun filerV490


your help would be appriciated,

thanks and regads,

nikunj