mmm_restore: 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
/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/sbin/mmm_restore - from package: mysql-mmm-tools

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

On Debian possible default full paths are:

/usr/sbin/mmm_restore - from package: mysql-mmm-tools

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