lsdahdi: 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/lsdahdi - from package: dahdi-tools

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

On Debian possible default full paths are:

/usr/sbin/lsdahdi - from package: dahdi

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

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