PROBLEM (zmstatd doesnt run)

[zimbra@mail ~]$ zmstatctl status

Running: zmstat-cpu
Running: zmstat-mysql
Running: zmstat-io-x
process 16010 in /opt/zimbra/zmstat/pid/zmstat-fd.pid not running
Running: zmstat-proc
Running: zmstat-df
Running: zmstat-vm
Running: zmstat-mtaqueue
Running: zmstat-allprocs
Running: zmstat-io

SOLUTION

[zimbra@mail ~]$ mv /opt/zimbra/zmstat/pid/zmstat-fd.pid  /opt/zimbra/zmstat/pid/zmstat-fd.pid.old
[zimbra@mail ~]$ zmcontrol stop && zmcontrol start  <<  restart zimbra server