Linux NTP服务配置for Oracle RAC教程

安装oracle 11g rac时，我们需要配置ntp服务。在使用的情况下对于时钟同步方式的配置有很多种方式，可以使用vmware自带的时钟同步功能，也可以直接将本地的一个节点用作时间服务器。本文介绍直接配置ntp方式的时钟服务器。

1、查看两节点的hosts配置

[root@node1 ~]# cat /etc/hosts

# do not remove the following line, or various programs

# that require network functionality will fail.

#127.0.0.1 localhost.localdomain localhost

#::1 localhost6.localdomain6 localhost6

127.0.0.1 localhost.szdb.com localhost

# public eth0

192.168.7.71 node1.szdb.com node1

192.168.7.72 node2.szdb.com node2

#private eth1

10.10.7.71 node1-priv.szdb.com node1-priv

10.10.7.72 node2-priv.szdb.com node2-priv

#virtual

192.168.7.81 node1-vip.szdb.com node1-vip

192.168.7.82 node2-vip.szdb.com node2-vip

2、确认各节点的ntp包已经安装

[oracle@node1 ~]$ rpm -qa | grep ntp

ntp-4.2.2p1-9.el5_4.1

chkfontpath-1.10.1-1.1 #这个是和字体有关，非ntp包

[oracle@node1 ~]$ ssh node2 rpm -qa | grep ntp

ntp-4.2.2p1-9.el5_4.1

chkfontpath-1.10.1-1.1 #这个是和字体有关，非ntp包

3、编辑两节点的ntp.conf文件

[oracle@node1 ~]$ su - root

password:

[root@node1 ~]# vi /etc/ntp.conf

#new ntp server added by robinson

server 127.127.1.0 prefer # 添加首选的时钟服务器

restrict 192.168.7.0 mask 255.255.255.255 nomodify notrap #只允许192.168.7.*网段的客户机进行时间同步

broadcastdelay 0.008

[root@node2 ~]# vi /etc/ntp.conf

#new ntp server added by robinson

server 192.168.7.71 prefer

broadcastdelay 0.008

4、编辑两节点的ntpd参数

[root@node1 ~]# vi /etc/sysconfig/ntpd

#the following item added by robinson

#set to 'yes' to sycn hw clock after successful ntpdate

sync_hwclock=yes #此选项用于自动校准时钟与硬件时钟

options="-x -u ntp:ntp -p /var/run/ntpd.pid"

#注意理解linux的时钟类型。在linux系统中分为系统时钟和硬件时钟.

#系统时钟指当前linux kernel中的时钟，而硬件时钟指的是bios时钟，由主板电池供电的那个时钟

#当linux启动时，硬件时钟会读取系统时钟的设置，之后系统时钟就独立于硬件时钟运作

[root@node2 ~]# vi /etc/sysconfig/ntpd

the following item added by robinson

sync_hwclock=yes

options="-x -u ntp:ntp -p /var/run/ntpd.pid"

5、配置ntp自启动服务

[root@node1 ~]# chkconfig ntpd on

[root@node2 ~]# chkconfig ntpd on

6、在两节点启动ntp服务

[root@node1 ~]# service ntpd stop

shutting down ntpd: [failed]

[root@node1 ~]# service ntpd start

ntpd: synchronizing with time server: [failed]

starting ntpd: [ ok ]

[root@node2 ~]# service ntpd restart

shutting down ntpd: [ ok ]

ntpd: synchronizing with time server: [ ok ]

syncing hardware clock to system time [ ok ]

starting ntpd: [ ok ]

7、查看ntp状态

[root@node1 ~]# ntpq -p

remote refid st t when poll reach delay offset jitter

==============================================================================

local(0) .locl. 10 l 40 64 1 0.000 0.000 0.001

[root@node2 ~]# ntpq -p

remote refid st t when poll reach delay offset jitter

==============================================================================

node1.szdb.com .init. 16 u 60 64 0 0.000 0.000 0.000

local(0) .locl. 10 l 59 64 1 0.000 0.000 0.001

#author : robinson

#blog: https://blog.csdn.net/robinson_0612

也可以使用watch ntpq -p方式查看实时状态

8、ntp的相关日志

[root@bigboy tmp]# cat /var/log/messages | grep ntpd