dmtcp_restart: 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/bin/dmtcp_restart - from package: dmtcp

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

On Debian possible default full paths are:

/usr/bin/dmtcp_restart - from package: dmtcp

You may install the required package with command apt-get install {package}

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