백업 예약
/home  /backup 로 백업하기로함
systemctl status crond

vi /etc/crontab
----------------------------
#추가  3시 15분 실행
01  3  15  *  *   root  run-parts /etc/cron.monthly
------------------------

cd /etc/cron.monthly/
vi myBackup.sh
=======================================
#@/bin/sh

set $(data)
fname="backup-$2$3.tar.xz"

tar cfJ /backup/$fname /home

===================================
chmod ugo+x myBackup.sh

mkdir /backup
systemctl restart crond