salt-ssh: 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/salt-ssh - from package: salt-ssh

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

On Debian possible default full paths are:

/usr/bin/salt-ssh - from package: salt-ssh

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

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