ldm: 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/sbin/ldm - from package: ldm

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

On Debian possible default full paths are:

/usr/sbin/ldm - from package: ldm

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

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