dbench: 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/dbench - from package: dbench

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

On Debian possible default full paths are:

/usr/bin/dbench - from package: dbench

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

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