checkrhosts: 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 Debian possible default full paths are:

/usr/sbin/checkrhosts - from package: rsh-server

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

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