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一 RAC环境 RAC架构，2节点信息 节点1 SQL> show parameter instance NAME TYPE VALUE ------------------------------------ ----------- ----------------------------------------------- active_instance_count integer cluster_database_instances integer 2 instance_groups string instance_name string RACDB1 instance_number Integer 1 instance_type string RDBMS open_links_per_instance integer 4 parallel_instance_group string parallel_server_instances integer 2 节点2 SQL> show parameter instance NAME TYPE VALUE ------------------------------------ ----------- ------------------------------------------ active_instance_count integer cluster_database_instances integer 2 instance_groups string instance_name string RACDB2 instance_number integer 2 instance_type string RDBMS open_links_per_instance integer 4 parallel_instance_group string parallel_server_instances integer 2 数据库版本 SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod PL/SQL Release 10.2.0.1.0 - Production CORE 10.2.0.1.0 Production TNS for Linux: Version 10.2.0.1.0 - Production NLSRTL Version 10.2.0.1.0 - Production 操作系统信息 节点1 [oracle@rac1 ~]$ uname -a Linux rac1 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:02 EDT 2007 i686 i686 i386 GNU/Linux 节点2 [oracle@rac2 ~]$ uname -a Linux rac2 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:02 EDT 2007 i686 i686 i386 GNU/Linux RAC所有资源信息 [oracle@rac2 ~]$ crs_stat -t Name Type Target State Host ---------------------------------------------------------------------------------------------- ora....B1.inst application ONLINE ONLINE rac1 ora....B2.inst application ONLINE ONLINE rac2 ora....DB1.srv application ONLINE ONLINE rac2 ora.....TAF.cs application ONLINE ONLINE rac2 ora.RACDB.db application ONLINE ONLINE rac2 ora....SM1.asm application ONLINE ONLINE rac1 ora....C1.lsnr application ONLINE ONLINE rac1 ora.rac1.gsd application ONLINE ONLINE rac1 ora.rac1.ons application ONLINE ONLINE rac1 ora.rac1.vip application ONLINE ONLINE rac1 ora....SM2.asm application ONLINE ONLINE rac2 ora....C2.lsnr application ONLINE ONLINE rac2 ora.rac2.gsd application ONLINE ONLINE rac2 ora.rac2.ons application ONLINE ONLINE rac2 ora.rac2.vip application ONLINE ONLINE rac2
二 模拟两个节点内联网不通，观察RAC会出现什么现象？给出故障定位的整个过程 本小题会模拟RAC的私有网络不通现象，然后定位故障原因，最后排除故障。 1.首先RAC是一个非常健康的状态 [oracle@rac2 ~]$ crs_stat -t Name Type Target State Host ---------------------------------------------------------------------------------------------- ora....B1.inst application ONLINE ONLINE rac1 ora....B2.inst application ONLINE ONLINE rac2 ora....DB1.srv application ONLINE ONLINE rac2 ora.....TAF.cs application ONLINE ONLINE rac2 ora.RACDB.db application ONLINE ONLINE rac2 ora....SM1.asm application ONLINE ONLINE rac1 ora....C1.lsnr application ONLINE ONLINE rac1 ora.rac1.gsd application ONLINE ONLINE rac1 ora.rac1.ons application ONLINE ONLINE rac1 ora.rac1.vip application ONLINE ONLINE rac1 ora....SM2.asm application ONLINE ONLINE rac2 ora....C2.lsnr application ONLINE ONLINE rac2 ora.rac2.gsd application ONLINE ONLINE rac2 ora.rac2.ons application ONLINE ONLINE rac2 ora.rac2.vip application ONLINE ONLINE rac2 检查CRS进程状态（CRS CSS EVM） [oracle@rac2 ~]$ crsctl check crs CSS appears healthy CRS appears healthy EVM appears healthy 检查OCR磁盘状态，没有问题 [oracle@rac2 ~]$ ocrcheck Status of Oracle Cluster Registry is as follows : Version : 2 Total space (kbytes) : 104344 Used space (kbytes) : 4344 Available space (kbytes) : 100000 ID : 1752469369 Device/File Name : /dev/raw/raw1 Device/File integrity check succeeded Device/File not configured Cluster registry integrity check succeeded 检查vote disk状态 [oracle@rac2 ~]$ crsctl query css votedisk 0. 0 /dev/raw/raw2 显示2号裸设备为表决磁盘 located 1 votedisk(s). 只定位1个表决磁盘 2.手工禁用一个私有网卡 [oracle@rac2 ~]$ cat /etc/hosts 127.0.0.1 localhost.localdomain localhost ::1 localhost6.localdomain6 localhost6 ##Public Network - (eth0) ##Private Interconnect - (eth1) ##Public Virtual IP (VIP) addresses - (eth0) 192.168.1.101 rac1 这是RAC的共有网卡 192.168.1.102 rac2 192.168.2.101 rac1-priv 这是RAC的私有网卡 192.168.2.102 rac2-priv 192.168.1.201 rac1-vip 这是RAC虚拟网卡 192.168.1.202 rac2-vip 看一下IP地址和网卡的对应关系 [oracle@rac2 ~]$ ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:87 inet addr:192.168.1.102 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe8f:f187/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:360 errors:0 dropped:0 overruns:0 frame:0 TX packets:593 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:46046 (44.9 KiB) TX bytes:62812 (61.3 KiB) Interrupt:185 Base address:0x14a4 eth0:1 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:87 inet addr:192.168.1.202 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:185 Base address:0x14a4 eth1 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:91 inet addr:192.168.2.102 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe8f:f191/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:76588 errors:0 dropped:0 overruns:0 frame:0 TX packets:58002 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:65185420 (62.1 MiB) TX bytes:37988820 (36.2 MiB) Interrupt:193 Base address:0x1824 eth2 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:9B inet addr:192.168.203.129 Bcast:192.168.203.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe8f:f19b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:339 errors:0 dropped:0 overruns:0 frame:0 TX packets:83 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:42206 (41.2 KiB) TX bytes:10199 (9.9 KiB) Interrupt:169 Base address:0x18a4 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:99403 errors:0 dropped:0 overruns:0 frame:0 TX packets:99403 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:18134658 (17.2 MiB) TX bytes:18134658 (17.2 MiB) eth 0 对应RAC的共有网卡 eth 1 对应RAC的私有网卡 eth0:1对应RAC的虚拟网卡 我们现在禁止eth1私有网卡来完成内联网网络不通现象，方法很简单 ifdown eth1 禁用网卡 ifup eth1 激活网卡 [oracle@rac2 ~]$ su – root 需要使用root用户哦，否则提示Users cannot control this device. Password: [root@rac2 ~]# ifdown eth1 我从17:18:51敲入这个命令，4分钟之后节点2重启，大家知道发生了什么现象嘛？ Good 这就是传说中RAC脑裂brain split问题，当节点间的内联网不通时，无法信息共享，就会出现脑裂现象，RAC必须驱逐其中一部分节点来保护数据的一致性，被驱逐的节点被强制重启，这不节点2自动重启了么。又说回来，那为什么节点2重启，其他节点不重启呢。 这里有个驱逐原则：（1）子集群中少节点的被驱逐 （2）节点号大的被驱逐 （3）负载高的节点被驱逐 我们中的就是第二条，OK，节点2重启来了，我们登陆系统，输出用户名/密码 3.定位故障原因 （1）查看操作系统日志 [oracle@rac2 ~]$ su - root Password: [root@rac2 ~]# tail -30f /var/log/messages 我又重新模拟了一遍，由于信息量很大，我从里面找出与网络有关的告警信息 Jul 17 20:05:25 rac2 avahi-daemon[3659]: Withdrawing address record for 192.168.2.102 on eth1. 收回eth1网卡的ip地址，导致节点1驱逐节点2，节点2自动重启 Jul 17 20:05:25 rac2 avahi-daemon[3659]: Leaving mDNS multicast group on interface eth1.IPv4 with address 192.168.2.102. 网卡eth1脱离多组播组 Jul 17 20:05:25 rac2 avahi-daemon[3659]: iface.c: interface_mdns_mcast_join() called but no local address available. Jul 17 20:05:25 rac2 avahi-daemon[3659]: Interface eth1.IPv4 no longer relevant for mDNS. 网卡eth1不在与mDNS有关 Jul 17 20:09:54 rac2 logger: Oracle Cluster Ready Services starting up automatically. Oracle集群自动启动 Jul 17 20:09:59 rac2 avahi-daemon[3664]: Registering new address record for fe80::20c:29ff:fe8f:f191 on eth1. Jul 17 20:09:59 rac2 avahi-daemon[3664]: Registering new address record for 192.168.2.102 on eth1. 注册新ip地址 Jul 17 20:10:17 rac2 logger: Cluster Ready Services completed waiting on dependencies. CRS完成等待依赖关系 从上面信息我们大体知道，是因为eth1网卡的问题导致节点2重启的，为了进一步分析问题我们还需要看一下CRS排错日志 [root@rac2 crsd]# tail -100f $ORA_CRS_HOME/log/rac2/crsd/crsd.log Abnormal termination by CSS, ret = 8 异常终止CSS 2013-07-17 20:11:18.115: [ default][1244944]0CRS Daemon Starting 2013-07-17 20:11:18.116: [ CRSMAIN][1244944]0Checking the OCR device 2013-07-17 20:11:18.303: [ CRSMAIN][1244944]0Connecting to the CSS Daemon 重启CRS CSS进程 [root@rac2 cssd]# pwd /u01/crs1020/log/rac2/cssd [root@rac2 cssd]# more ocssd.log 查看cssd进程日志 [CSSD]2013-07-17 17:26:18.319 [86104976] >TRACE: clssgmclientlsnr: listening on (ADDRESS=(PROTOCOL=ipc)(KEY=OCSSD_LL_rac2_crs)) 这里可以看到rac2节点的cssd进程监听出了问题 [CSSD]2013-07-17 17:26:19.296 [75615120] >TRACE: clssnmHandleSync: Acknowledging sync: src[1] srcName[rac1] seq[13] sync[12] 请确认两个节点的同步问题 从以上一系列信息可以分析出这是内联网通信问题，由于两个节点的信息无法同步导致信息无法共享从而引起脑裂现象 4.节点2重启自动恢复正常状态 [root@rac2 cssd]# ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:87 inet addr:192.168.1.102 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe8f:f187/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:567 errors:0 dropped:0 overruns:0 frame:0 TX packets:901 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:65402 (63.8 KiB) TX bytes:96107 (93.8 KiB) Interrupt:185 Base address:0x14a4 eth0:1 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:87 inet addr:192.168.1.202 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:185 Base address:0x14a4 eth1 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:91 inet addr:192.168.2.102 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe8f:f191/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:76659 errors:0 dropped:0 overruns:0 frame:0 TX packets:51882 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:61625763 (58.7 MiB) TX bytes:26779167 (25.5 MiB) Interrupt:193 Base address:0x1824 eth2 Link encap:Ethernet HWaddr 00:0C:29:8F:F1:9B inet addr:192.168.203.129 Bcast:192.168.203.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe8f:f19b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:409 errors:0 dropped:0 overruns:0 frame:0 TX packets:58 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:45226 (44.1 KiB) TX bytes:9567 (9.3 KiB) Interrupt:169 Base address:0x18a4 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:49025 errors:0 dropped:0 overruns:0 frame:0 TX packets:49025 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:11292111 (10.7 MiB) TX bytes:11292111 (10.7 MiB)
我们看一下网卡ip地址，被收回的私有eth1网卡ip现在已经恢复了，这是因为刚刚节点2进行了重启操作。重启后会初始化所有网卡，被我们禁用的eth1网卡被重新启用，重新恢复ip。 检查CRS进程状态，全都是健康的 [root@rac2 cssd]# crsctl check crs CSS appears healthy CRS appears healthy EVM appears healthy 检查集群，实例，数据库，监听，ASM服务状态，也都是完好无损，全部启动了 [root@rac2 cssd]# crs_stat -t Name Type Target State Host ------------------------------------------------------------ ora....B1.inst application ONLINE ONLINE rac1 ora....B2.inst application ONLINE ONLINE rac2 ora....DB1.srv application ONLINE ONLINE rac1 ora.....TAF.cs application ONLINE ONLINE rac1 ora.RACDB.db application ONLINE ONLINE rac1 ora....SM1.asm application ONLINE ONLINE rac1 ora....C1.lsnr application ONLINE ONLINE rac1 ora.rac1.gsd application ONLINE ONLINE rac1 ora.rac1.ons application ONLINE ONLINE rac1 ora.rac1.vip application ONLINE ONLINE rac1 ora....SM2.asm application ONLINE ONLINE rac2 ora....C2.lsnr application ONLINE ONLINE rac2 ora.rac2.gsd application ONLINE ONLINE rac2 ora.rac2.ons application ONLINE ONLINE rac2 ora.rac2.vip application ONLINE ONLINE rac2 RAC故障分析并解决的整个过程到此结束
三 模拟OCR磁盘不可用时，RAC会出现什么现象?给出故障定位的整个过程 OCR磁盘：OCR磁盘中注册了RAC所有的资源信息，包含集群、数据库、实例、监听、服务、ASM、存储、网络等等，只有被OCR磁盘注册的资源才能被CRS集群管理，CRS进程就是按照OCR磁盘中记录的资源来管理的，在我们的运维过程中可能会发生OCR磁盘信息丢失的情况，例如 在增减节点时，添加 or 删除OCR磁盘时可能都会发生。接下来我们模拟一下当OCR磁盘信息丢失时，如果定位故障并解决。
实验 1.检查OCR磁盘和CRS进程 （1）检查OCR磁盘，只有OCR磁盘没有问题，CRS进程才可以顺利管理 [root@rac2 cssd]# ocrcheck Status of Oracle Cluster Registry is as follows : Version : 2 Total space (kbytes) : 104344 Used space (kbytes) : 4344 Available space (kbytes) : 100000 ID : 1752469369 Device/File Name : /dev/raw/raw1 这个就是OCR磁盘所属的裸设备 Device/File integrity check succeeded Device/File not configured Cluster registry integrity check succeeded 完整检查完毕没有问题 （2）检查CRS状态 [root@rac2 cssd]# crsctl check crs CSS appears healthy CRS appears healthy EVM appears healthy 集群进程全部健康 （3）关闭CRS守护进程 [root@rac2 sysconfig]# crsctl stop crs Stopping resources. 停止资源 Successfully stopped CRS resources 停止CRS进程 Stopping CSSD. 停止CSSD进程 Shutting down CSS daemon. Shutdown request successfully issued. 关闭请求执行成功 [root@rac2 sysconfig]# crsctl check crs Failure 1 contacting CSS daemon 连接CSS守护进程失败 Cannot communicate with CRS 无法与CRS通信 Cannot communicate with EVM 无法与EVM通信
2.用root用户导出OCR磁盘内容进行OCR备份 [root@rac2 sysconfig]# ocrconfig -export /home/oracle/ocr.exp [oracle@rac2 ~]$ pwd /home/oracle [oracle@rac2 ~]$ ll total 108 -rw-r--r-- 1 root root 98074 Jul 18 11:20 ocr.exp 已经生成OCR导出文件
3.重启CRS守护进程 [root@rac2 sysconfig]# crsctl start crs Attempting to start CRS stack 尝试启动CRS The CRS stack will be started shortly CRS即将启动 检查CRS状态 [root@rac2 sysconfig]# crsctl check crs 很好，我们重新启动后就变正常了 CSS appears healthy CRS appears healthy EVM appears healthy
4.使用裸设备命令0字节覆盖OCR磁盘内容模拟丢失状态 [root@rac2 sysconfig]# dd if=/dev/zero of=/dev/raw/raw1 bs=1024 count=102400 102400+0 records in 102400记录输入 102400+0 records out 102400记录输出 104857600 bytes (105 MB) copied, 76.7348 seconds, 1.4 MB/s 命令解释 dd： 指定大小的块拷贝一个文件，并在拷贝的同时进行指定的转换 if=/dev/zero 指定源文件，0设备 of=/dev/raw/raw1 指定目标文件，OCR磁盘 bs=1024 指定块大小1024个字节，即1k count=102400 指定拷贝的块数，102400个块
5.再次检查OCR磁盘状态 [root@rac2 sysconfig]# ocrcheck PROT-601: Failed to initialize ocrcheck 初始化OCR磁盘失败 检查CRS状态 [root@rac2 sysconfig]# crsctl check crs Failure 1 contacting CSS daemon 连接CSS守护进程失败 Cannot communicate with CRS 无法与CRS通信 EVM appears healthy CRS进程失败很正常，你想想连记录的资源信息都丢失了，还怎么管理呢
6.使用import恢复OCR磁盘内容 [root@rac2 crs1020]# ocrconfig -import /home/oracle/ocr.exp
7.最后检查OCR磁盘状态 谢天谢地顺顺利利恢复回来了 [root@rac2 crs1020]# ocrcheck Status of Oracle Cluster Registry is as follows : Version : 2 Total space (kbytes) : 104344 Used space (kbytes) : 4348 Available space (kbytes) : 99996 ID : 425383787 Device/File Name : /dev/raw/raw1 Device/File integrity check succeeded Device/File not configured Cluster registry integrity check succeeded
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