這篇文章將為大家詳細(xì)講解有關(guān)如何在各個平臺上配置NTP的微調(diào)模式，文章內(nèi)容質(zhì)量較高，因此小編分享給大家做個參考，希望大家閱讀完這篇文章后對相關(guān)知識有一定的了解。
對于11.2之前的版本，很多環(huán)境的重啟原因（top5的情況）是由于NTP調(diào)整時間的步伐過大導(dǎo)致的，所以RAC環(huán)境中，我們建議用戶如果使用NTP，需要配置成微調(diào)模式；
如何診斷節(jié)點(diǎn)重啟問題
這里介紹幾個主流linux和unix平臺上NTP微調(diào)的配置方法：
For Linux ：
1.請確確認(rèn)各節(jié)點(diǎn)的ntp包已經(jīng)安裝 ,我這里是個4.2.2的版本
[oracle@nascds10 ~]$ rpm -qa | grep ntp
ntp-4.2.2p1-9.el5_4.1
2.請編輯各個節(jié)點(diǎn)的ntp.conf文件
[oracle@nascds10 ~]$ su - root
Password:
[root@nascds10 ~]# vi /etc/ntp.conf
#New ntp server added by Robinson
server 192.168.1.128 prefer <<<<===========這里是時鐘服務(wù)器
restrict 192.168.7.0 mask 255.255.255.255 nomodify notrap #基于網(wǎng)段的限制（限制在網(wǎng)段192.168.7.0）
broadcastdelay 0.008
[root@nascds11 ~]# vi /etc/ntp.conf
#New ntp server added by Robinson
server 192.168.7.71 prefer
broadcastdelay 0.008
3、配置ntpd的參數(shù)，我們主要強(qiáng)調(diào)的是要配置成"微調(diào)的模式" 也就是在options中要加入 -x的選項(xiàng)
[root@nascds10 ~]# vi /etc/sysconfig/ntpd
#The following item added by Robinson
#Set to 'yes' to sycn hw clock after successful ntpdate
SYNC_HWCLOCK=yes
OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid"
[root@nascds11 ~]# vi /etc/sysconfig/ntpd
The following item added by Robinson
SYNC_HWCLOCK=yes
OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid"
4、自動啟動配置
[root@nascds10 ~]# chkconfig ntpd on
[root@nascds11 ~]# chkconfig ntpd on
5、重啟一下，使最新配置生效
[root@nascds10 ~]# service ntpd restart
Shutting down ntpd: [ OK ]
ntpd: Synchronizing with time server: [ OK ]
Syncing hardware clock to system time [ OK ]
Starting ntpd: [ OK ]
[root@nascds11 ~]# service ntpd restart
Shutting down ntpd: [ OK ]
ntpd: Synchronizing with time server: [ OK ]
Syncing hardware clock to system time [ OK ]
Starting ntpd: [ OK ]
6、檢查ntpd進(jìn)程的狀態(tài)
[root@nascds10 ~]# 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@nascds11 ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
test.oracle.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
For Aix:
1. NTP的同步設(shè)置 編輯 /etc/ntp.conf文件, 內(nèi)容如下:
----------------------------
#broadcastclient
server 192.168.5.2
driftfile /etc/ntp.drift
tracefile /etc/ntp.trace
slewalways yes
----------------------------
我們這里還是要強(qiáng)調(diào)微調(diào)slewalways ,這個值的默認(rèn)設(shè)置是no，也就是說如果您不設(shè)置，NTP大可一次調(diào)整1000秒. 根據(jù)IBM的官方說明，如果我們不指定slewthreshold 那么默認(rèn)值是 0.128 seconds. 如果想特別設(shè)置，請指定slewthreshold 的值，注意單位是second
2.在NTP客戶端啟動xntpd守護(hù)進(jìn)程
# startsrc -s xntpd
3. 查詢xntpd的狀態(tài)
當(dāng) system peer 不為 'insane' 時, 表明客戶端已與服務(wù)器端成功地進(jìn)行了同步.
# lssrc -ls xntpd
Program name: --/usr/sbin/xntpd
Version: -------3
Leap indicator: 00 (No leap second today.) Sys peer: ------192.168.5.2 ...
關(guān)于更多的關(guān)于IBM的平臺上NTP的設(shè)置，可以參考IBM的官方文檔解釋：
http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.files/doc/aixfiles/ntp.conf.htm
For HP UX:
NTP在HP上的配置，是比較省心的，不容易導(dǎo)致RAC重啟的，因?yàn)镠P上的NTP默認(rèn)的就是微調(diào)的模式
1、首先我們還是要編輯ntp的配置文件 /etc/rc.config.d/netdaemons，把 XNTPD 設(shè)定為1表示啟動
export XNTPD=1
2、編輯配置文件 /etc/ntp.conf ，配置好時間同步服務(wù)器
server 192.168.5.2 # 第一個地址是主服務(wù)器
server 192.168.5.3 # 第二個地址是備用服務(wù)器
3、啟動ntp的進(jìn)程
# /sbin/init.d/xntpd start
4、檢查NTP的狀態(tài)
# /usr/sbin/ntpq -p
這個命令您會看到同步的地址
如果出現(xiàn)的結(jié)果是No association ID's returned 那么表示您失敗了
關(guān)于HP主機(jī)上NTP的模式，有3種如下，在HP 平臺的man page中有詳細(xì)的說明：
模式1：offset below 128 milliseconds
This is the normal operating regime of NTP. A properly configured NTP hierarchy (with reasonable networking) can operate for years without ever approaching the 128 millisecond upper limit. All time adjustments are small and smooth (known as slewing), and nobody even notices the slew adjustments unless they have a cesium clock or a GPS clock and expensive instrumentation to make sophisticated measurements (HP/Agilent makes the instruments).
模式2：offset above 128 milliseconds
This regime is often encountered at power-on because, those battery-backed real-time clocks they put in computers are not too great. Because NTP is quite capable of keeping the offset below one millisecond all the time it is running, many users want to get into the normal regime quickly when an offset above 128 millisecond is encountered at startup. So in this situation NTP will (fairly quickly) make a single step change, and is usually successful in getting the offset well below 128 millisecond so there will be no more of the disruptive step changes.
模式3：offset above 1000 seconds
This is so far out of the normal operating range that NTP decides something is terribly wrong and human intervention is required. The daemon shuts down.
For Solars:
我這沒有測試的平臺，不過在KM (How to Configure NTP or Windows Time for Oracle Clusterware (Doc ID 1056693.1))里找到了配置的辦法，這里還有Windows的配置方式
檢查配置:
/usr/bin/svcs ntp
STATE STIME FMRI
online 7:39:29 svc:/network/ntp:default
ps -ef|grep ntp
root 21212 1 0 Feb 02 ? 0:33 /usr/lib/inet/xntpd
配置/etc/inet/ntp.conf 啟用slewalaways
grep 'slewalways|pll' /etc/inet/ntp.conf
slewalways yes
disable pll
啟動:
/usr/sbin/svcadm enable ntp
關(guān)于如何在各個平臺上配置NTP的微調(diào)模式就分享到這里了，希望以上內(nèi)容可以對大家有一定的幫助，可以學(xué)到更多知識。如果覺得文章不錯，可以把它分享出去讓更多的人看到。
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