pvdataserver_mpich: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/lib64/mpich/bin/pvdataserver_mpich - from package: paraview-mpich

You may install the required package with command yum install {package}

Error in other languages:
pvdataserver_mpich: bevel nie gevind nie
pvdataserver_mpich: comandă negăsită
pvdataserver_mpich: comando não encontrado
pvdataserver_mpich: commande introuvable
pvdataserver_mpich: command not found
pvdataserver_mpich: käsku ei ole
pvdataserver_mpich: không tìm thấy lệnh
pvdataserver_mpich: komanda nerasta
pvdataserver_mpich: Kommando nicht gefunden.
pvdataserver_mpich: kommandot finns inte
pvdataserver_mpich: komut yok
pvdataserver_mpich: nie znaleziono polecenia
pvdataserver_mpich: níor aimsíodh an t-ordú
pvdataserver_mpich: no se encontró la orden
pvdataserver_mpich: no s'ha trobat l'ordre
pvdataserver_mpich: opdracht niet gevonden
pvdataserver_mpich: parancs nem található
pvdataserver_mpich: perintah tidak ditemukan
pvdataserver_mpich: príkaz nenájdený
pvdataserver_mpich: příkaz nenalezen
pvdataserver_mpich: команда не найдена
pvdataserver_mpich: командата не е открита
pvdataserver_mpich: 命令找不到
pvdataserver_mpich: コマンドが見つかりません