dmeventd: 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:

/sbin/dmeventd - from package: device-mapper-event

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

On Debian possible default full paths are:

/sbin/dmeventd - from package: dmeventd

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

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