snmpusm: 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/snmpusm - from package: net-snmp-utils

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

On Debian possible default full paths are:

/usr/bin/snmpusm - from package: snmp

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

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