setsid: 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/setsid - from package: util-linux-ng

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

On Debian possible default full paths are:

/usr/bin/setsid - from package: util-linux

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

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