linux-user-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 CentOS possible default full paths are:

/usr/bin/linux-user-chroot - from package: linux-user-chroot

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

On Debian possible default full paths are:

/usr/bin/linux-user-chroot - from package: linux-user-chroot

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

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