Ceph 時鍾偏移問題 clock skew detected 解決方案--- 部署內網NTP服務

告警：HEALTH_WARN clock skew detected on mon.ip-10-25-195-6; 8 requests are blocked > 32 sec; Monitor clock skew detected 

 

原因：

MON可能被MON節點之間的重要的時鍾偏移激烈的影響。這經常會轉變為沒有明顯原因的詭異的行為。為了避免這種問題，你應該在MON節點上運行一個時間同步的工具。

默認最大容忍的時鍾偏移為0.05s，不建議修改這個官方開發推薦值。私自未經測試修改雖然無數據丟失風險，可能會對MON集群和總體集群健康導致意外的作用。

如果你遇到這個告警，同步時鍾，在MON上運行NTP的客戶端會有幫助。如果經常遇到這個問題，可能是因為使用了遠端的NTP服務器，請考慮在內網部署NTP服務器。

 

在MON/OSD/RGW節點部署NTP服務的操作步驟：

1. apt-get install ntp
2. 修改ntp配置 /etc/ntp.conf
3. 重啟ntp服務

 /etc/ntp.conf

# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
#sync time interval
tinker step 0.5 

driftfile /var/lib/ntp/ntp.drift

# Enable this if you want statistics to be logged.
#statsdir /var/log/ntpstats/

statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable

# Specify one or more NTP servers.

# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# YY NTP servers 
server 121.14.36.27   iburst
server 221.228.209.14 iburst
server 183.57.81.221  iburst
server 113.142.33.209 iburst
server 106.38.198.9   iburst

# Use Ubuntu's ntp server as a fallback.
#pool ntp.ubuntu.com

# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
# details.  The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
# might also be helpful.
#
# Note that "restrict" applies to both servers and clients, so a configuration
# that might be intended to block requests from certain clients could also end
# up blocking replies from your own upst