ltsp-info: 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 Debian possible default full paths are:

/usr/bin/ltsp-info - from package: ltsp-server

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

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