ltsp-chroot: 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/sbin/ltsp-chroot - from package: ltsp-server

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

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