----------
20190609


檢查cent os 版本:
# cat /etc/system-release
CentOS Linux release 7.5.1804 (Core) (家裡的版本)
CentOS Linux release 7.0.1406 (Core)

# cat /proc/version
Linux version 3.10.0-693.21.1.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) ) #1 SMP Wed Mar 7 19:03:37 UTC 2018
     Linux version 3.10.0-123.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.2 20140120 (Red Hat 4.8.2-16) (GCC) ) #1 SMP Mon Jun 30 12:09:22 UTC 2014