ruby-benchmark-suite: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/bin/ruby-benchmark-suite - from package: ruby-benchmark-suite

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