migrateto17.php: 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/share/doc/php-sabre-dav-1.8.12/bin/migrateto17.php - from package: php-sabre-dav

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

Error in other languages:
migrateto17.php: bevel nie gevind nie
migrateto17.php: comandă negăsită
migrateto17.php: comando não encontrado
migrateto17.php: commande introuvable
migrateto17.php: command not found
migrateto17.php: käsku ei ole
migrateto17.php: không tìm thấy lệnh
migrateto17.php: komanda nerasta
migrateto17.php: Kommando nicht gefunden.
migrateto17.php: kommandot finns inte
migrateto17.php: komut yok
migrateto17.php: nie znaleziono polecenia
migrateto17.php: níor aimsíodh an t-ordú
migrateto17.php: no se encontró la orden
migrateto17.php: no s'ha trobat l'ordre
migrateto17.php: opdracht niet gevonden
migrateto17.php: parancs nem található
migrateto17.php: perintah tidak ditemukan
migrateto17.php: príkaz nenájdený
migrateto17.php: příkaz nenalezen
migrateto17.php: команда не найдена
migrateto17.php: командата не е открита
migrateto17.php: 命令找不到
migrateto17.php: コマンドが見つかりません