■概要
CentOSのサーバの時刻を自動的に日本標準時間に合わせる設定を行います。こちらの設定を行うことで時刻に対するシステムトラブルを未然に防げることができますので、CentOSを日本国内で稼働させるには設定が必要です。
文字色の説明 ■説明文 ■コマンド(Input) ■注意事項
NTPサーバインストール
[root@hostname ~]# yum -y install ntp ⇐ インストール
NTPサーバ設定
[root@hostname ~]# vi /etc/ntp.com ⇐ 設定ファイルを開く
# For more information about this file, see the man pages
# ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5).
driftfile /var/lib/ntp/drift
# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
# Permit all access over the loopback interface. This could
# be tightened as well, but to do so would effect some of
# the administrative functions.
restrict 127.0.0.1
restrict -6 ::1
# Hosts on local network are less restricted.
#restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap ⇐ 自分のネットワーク追加
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst
server ntp.nict.jp ⇐ 追加
server ntp.jst.mfeed.ad.jp ⇐ 追加
#broadcast 192.168.1.255 autokey # broadcast server
#broadcastclient # broadcast client
#broadcast 224.0.1.1 autokey # multicast server
#multicastclient 224.0.1.1 # multicast client
#manycastserver 239.255.254.254 # manycast server
#manycastclient 239.255.254.254 autokey # manycast client
# Enable public key cryptography.
#crypto
includefile /etc/ntp/crypto/pw
# Key file containing the keys and key identifiers used when operating
# with symmetric key cryptography.
keys /etc/ntp/keys
# Specify the key identifiers which are trusted.
#trustedkey 4 8 42
# Specify the key identifier to use with the ntpdc utility.
#requestkey 8
# Specify the key identifier to use with the ntpq utility.
#controlkey 8
# Enable writing of statistics records.
#statistics clockstats cryptostats loopstats peerstats
NTPサーバ起動と自動起動設定
[root@hostname ~]# etc/rc.d/init.d/ntpd start ⇐ 起動設定
ntpd を起動中: [ OK ]
[root@hostname ~]# chkconfig ntpd on ⇐ 自動起動設定
NTPサーバ設定確認
[root@hostname ~]# ntpq -p ⇐ 時刻同期確認
remote refid st t when poll reach delay offset jitter
============================================================================
+ntp3.jst.mfeed. 133.243.236.17 2 u 656 1024 377 6.912 33.653 0.556
※サーバ名の前に「+」または「*」が表示されれば時刻の同期状況は完了