[root@amahitest html]# cat /var/run/hdactl.pid
2997
[root@amahitest html]# ps aux | grep hdactl
root      2999  0.0  0.7 143396  7336 pts/0    S    15:03   0:00 /usr/bin/perl -w /usr/bin/hdactl
root      3008  0.0  0.0 103152   804 pts/0    S+   15:04   0:00 grep hdactl