Oracle Rac 添加节点测试笔记
一、测试环境
| 主机名 | 实例名 | 操作系统 | 数据库版本 |
| rac1 | racdb1 | RHEL 6.5 64位 | 11.2.0.4.0 |
| rac2 | racdb2 | RHEL 6.5 64位 | 11.2.0.4.0 |
| rac3（添加） | racdb3 | RHEL 6.5 64位 | 11.2.0.4.0 |
| rac4（添加） | racdb4 | RHEL 6.5 64位 | 11.2.0.4.0 |
二、添加节点
1、准备工作
- 在节点3、4中配置IP，并配置本地host文件，修改节点1、2的host文件与节点3、4一致；
- 配置共享存储，可以同时访问节点1、2的存储，并配置udev，参照节点1、2的配置；
- 安装补丁包，参照节点1、2的配置；
- 关闭防火墙和 SEILINXU，参照节点1、2的配置；
- 为 Grid Infrastructure创建组和用户，并修改grid用户下.bash_profile参数，参照节点1、2的配置；
- 为 Oracle 数据库软件创建组和用户，并修改用户下.bash_profile参数，参照节点1、2的配置；
- 创建 Oracle 基目录路径并设定权限，参照节点1、2的配置；
- 修改 /etc/security/limits.conf 的参数，参照节点1、2的配置；
- 修改 /etc/pam.d/login 的参数，参照节点1、2的配置；
- 修改 /etc/profile 的参数，参照节点1、2的配置；
- 修改 /etc/csh.login 的参数，参照节点1、2的配置；
- 配置内核参数 /etc/sysctl.conf ，参照节点1、2的配置；
- 配置4节点间ssh互通性，参照节点1、2的配置。
以上步骤可以参照如下博文：
Oracle 11gr2 RAC安装笔记（四）安装Grid Infrastructure
2、扩展集群节点
- 执行前检查：
在rac1上进入grid用户执行：
cluvfy stage -post hwos -n rac3,rac4 -verbose
cluvfy comp peer -refnode rac2 -n rac3,rac4 -orainv oinstall -osdba asmdba -verbose
cluvfy stage -pre nodeadd -n rac3,rac4 -fixup -fixupdir /tmp/fixup_dir -verbose-
执行添加脚本：
在rac1上进入grid用户执行：
export IGNORE_PREADDNODE_CHECKS=Y
cd $ORACLE_HOME/oui/bin
./addNode.sh -silent "CLUSTER_NEW_NODES={rac3,rac4}" "CLUSTER_NEW_VIRTUAL_HOSTNAMES={rac3-vip,rac4-vip}"过程如下：
[[email protected] bin]$ ./addNode.sh -silent "CLUSTER_NEW_NODES={rac3,rac4}" "CLUSTER_NEW_VIRTUAL_HOSTNAMES={rac3-vip,rac4-vip}"
Starting Oracle Universal Installer...Checking swap space: must be greater than 500 MB. Actual 4095 MB Passed
Oracle Universal Installer, Version 11.2.0.4.0 Production
Copyright (C) 1999, 2013, Oracle. All rights reserved.
Performing tests to see whether nodes rac2,rac3,rac4 are available
............................................................... 100% Done..
-----------------------------------------------------------------------------
Cluster Node Addition Summary
Global Settings
Source: /u01/app/11.2.0/grid
New Nodes
Space Requirements
New Nodes
rac3
/: Required 5.15GB : Available 34.10GB
rac4
/: Required 5.15GB : Available 34.12GB
Installed Products
Product Names
Oracle Grid Infrastructure 11g 11.2.0.4.0
Java Development Kit 1.5.0.51.10
Installer SDK Component 11.2.0.4.0
Oracle One-Off Patch Installer 11.2.0.3.4
Oracle Universal Installer 11.2.0.4.0
Oracle RAC Required Support Files-HAS 11.2.0.4.0
Oracle USM Deconfiguration 11.2.0.4.0
Oracle Configuration Manager Deconfiguration 10.3.1.0.0
Enterprise Manager Common Core Files 10.2.0.4.5
Oracle DBCA Deconfiguration 11.2.0.4.0
Oracle RAC Deconfiguration 11.2.0.4.0
Oracle Quality of Service Management (Server) 11.2.0.4.0
Installation Plugin Files 11.2.0.4.0
Universal Storage Manager Files 11.2.0.4.0
Oracle Text Required Support Files 11.2.0.4.0
Automatic Storage Management Assistant 11.2.0.4.0
Oracle Database 11g Multimedia Files 11.2.0.4.0
Oracle Multimedia Java Advanced Imaging 11.2.0.4.0
Oracle Globalization Support 11.2.0.4.0
Oracle Multimedia Locator RDBMS Files 11.2.0.4.0
Oracle Core Required Support Files 11.2.0.4.0
Bali Share 1.1.18.0.0
Oracle Database Deconfiguration 11.2.0.4.0
Oracle Quality of Service Management (Client) 11.2.0.4.0
Expat libraries 2.0.1.0.1
Oracle Containers for Java 11.2.0.4.0
Perl Modules 5.10.0.0.1
Secure Socket Layer 11.2.0.4.0
Oracle JDBC/OCI Instant Client 11.2.0.4.0
Oracle Multimedia Client Option 11.2.0.4.0
LDAP Required Support Files 11.2.0.4.0
Character Set Migration Utility 11.2.0.4.0
Perl Interpreter 5.10.0.0.2
PL/SQL Embedded Gateway 11.2.0.4.0
OLAP SQL Scripts 11.2.0.4.0
Database SQL Scripts 11.2.0.4.0
Oracle Extended Windowing Toolkit 3.4.47.0.0
SSL Required Support Files for InstantClient 11.2.0.4.0
SQL*Plus Files for Instant Client 11.2.0.4.0
Oracle Net Required Support Files 11.2.0.4.0
Oracle Database User Interface 2.2.13.0.0
RDBMS Required Support Files for Instant Client 11.2.0.4.0
RDBMS Required Support Files Runtime 11.2.0.4.0
XML Parser for Java 11.2.0.4.0
Oracle Security Developer Tools 11.2.0.4.0
Oracle Wallet Manager 11.2.0.4.0
Enterprise Manager plugin Common Files 11.2.0.4.0
Platform Required Support Files 11.2.0.4.0
Oracle JFC Extended Windowing Toolkit 4.2.36.0.0
RDBMS Required Support Files 11.2.0.4.0
Oracle Ice Browser 5.2.3.6.0
Oracle Help For Java 4.2.9.0.0
Enterprise Manager Common Files 10.2.0.4.5
Deinstallation Tool 11.2.0.4.0
Oracle Java Client 11.2.0.4.0
Cluster Verification Utility Files 11.2.0.4.0
Oracle Notification Service (eONS) 11.2.0.4.0
Oracle LDAP administration 11.2.0.4.0
Cluster Verification Utility Common Files 11.2.0.4.0
Oracle Clusterware RDBMS Files 11.2.0.4.0
Oracle Locale Builder 11.2.0.4.0
Oracle Globalization Support 11.2.0.4.0
Buildtools Common Files 11.2.0.4.0
HAS Common Files 11.2.0.4.0
SQL*Plus Required Support Files 11.2.0.4.0
XDK Required Support Files 11.2.0.4.0
Agent Required Support Files 10.2.0.4.5
Parser Generator Required Support Files 11.2.0.4.0
Precompiler Required Support Files 11.2.0.4.0
Installation Common Files 11.2.0.4.0
Required Support Files 11.2.0.4.0
Oracle JDBC/THIN Interfaces 11.2.0.4.0
Oracle Multimedia Locator 11.2.0.4.0
Oracle Multimedia 11.2.0.4.0
Assistant Common Files 11.2.0.4.0
Oracle Net 11.2.0.4.0
PL/SQL 11.2.0.4.0
HAS Files for DB 11.2.0.4.0
Oracle Recovery Manager 11.2.0.4.0
Oracle Database Utilities 11.2.0.4.0
Oracle Notification Service 11.2.0.3.0
SQL*Plus 11.2.0.4.0
Oracle Netca Client 11.2.0.4.0
Oracle Advanced Security 11.2.0.4.0
Oracle JVM 11.2.0.4.0
Oracle Internet Directory Client 11.2.0.4.0
Oracle Net Listener 11.2.0.4.0
Cluster Ready Services Files 11.2.0.4.0
Oracle Database 11g 11.2.0.4.0
-----------------------------------------------------------------------------
Instantiating scripts for add node (Wednesday, January 16, 2019 3:42:37 PM CST)
. 1% Done.
Instantiation of add node scripts completeCopying to remote nodes (Wednesday, January 16, 2019 3:42:42 PM CST)
............................................................................................... 96% Done.
Home copied to new nodesSaving inventory on nodes (Wednesday, January 16, 2019 3:47:19 PM CST)
. 100% Done.
Save inventory complete
WARNING:A new inventory has been created on one or more nodes in this session. However, it has not yet been registered as the central inventory of this system.
To register the new inventory please run the script at '/u01/app/oraInventory/orainstRoot.sh' with root privileges on nodes 'rac3,rac4'.
If you do not register the inventory, you may not be able to update or patch the products you installed.
The following configuration scripts need to be executed as the "root" user in each new cluster node. Each script in the list below is followed by a list of nodes.
/u01/app/oraInventory/orainstRoot.sh #On nodes rac3,rac4
/u01/app/11.2.0/grid/root.sh #On nodes rac3,rac4
To execute the configuration scripts:
1. Open a terminal window
2. Log in as "root"
3. Run the scripts in each cluster node
The Cluster Node Addition of /u01/app/11.2.0/grid was successful.
Please check '/tmp/silentInstall.log' for more details.
根据上面英文提示，需要以root用户分别在rac3、rac4上执行命令：
/u01/app/oraInventory/orainstRoot.sh按顺序在rac3、rac4上执行命令：
/u01/app/11.2.0/grid/root.sh- 添加节点后检查
在rac1上进入grid用户执行：
cluvfy stage -post nodeadd -n rac3,rac4 -verbose除SCAN检查失败外，其余全部通过，SCAN检查失败可以忽略。
在四个节点上都执行如下命令，查看结果是否一致：
crsctl stat res -t结果如下：
[[email protected] ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
NAME TARGET STATE SERVER STATE_DETAILS
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.CRS.dg
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.DATA.dg
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.LISTENER.lsnr
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.asm
ONLINE ONLINE rac1 Started
ONLINE ONLINE rac2 Started
ONLINE ONLINE rac3 Started
ONLINE ONLINE rac4 Started
ora.gsd
OFFLINE OFFLINE rac1
OFFLINE OFFLINE rac2
OFFLINE OFFLINE rac3
OFFLINE OFFLINE rac4
ora.net1.network
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.ons
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.registry.acfs
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE rac2
ora.cvu
1 ONLINE ONLINE rac2
ora.oc4j
1 ONLINE ONLINE rac2
ora.rac1.vip
1 ONLINE ONLINE rac1
ora.rac2.vip
1 ONLINE ONLINE rac2
ora.rac3.vip
1 ONLINE ONLINE rac3
ora.rac4.vip
1 ONLINE ONLINE rac4
ora.racdb.db
1 ONLINE ONLINE rac1 Open
2 ONLINE ONLINE rac2 Open
ora.scan1.vip
1 ONLINE ONLINE rac2
3、扩展DB HOME
在节点rac1上以oracle用户执行以下命令：
cd $ORACLE_HOME/oui/bin
./addNode.sh -silent "CLUSTER_NEW_NODES={rac3,rac4}"过程如下：
[[email protected] bin]$ ./addNode.sh -silent "CLUSTER_NEW_NODES={rac3,rac4}"
Performing pre-checks for node addition
Checking node reachability...
Node reachability check passed from node "rac1"
Checking user equivalence...
User equivalence check passed for user "oracle"WARNING:
Node "rac3" already appears to be part of clusterWARNING:
Node "rac4" already appears to be part of clusterPre-check for node addition was successful.
Starting Oracle Universal Installer...Checking swap space: must be greater than 500 MB. Actual 4095 MB Passed
Oracle Universal Installer, Version 11.2.0.4.0 Production
Copyright (C) 1999, 2013, Oracle. All rights reserved.
Performing tests to see whether nodes rac2,rac3,rac4 are available
............................................................... 100% Done...
-----------------------------------------------------------------------------
Cluster Node Addition Summary
Global Settings
Source: /u01/app/oracle/product/11.2.0/dbhome_1
New Nodes
Space Requirements
New Nodes
rac3
/: Required 4.24GB : Available 30.19GB
rac4
/: Required 4.24GB : Available 30.21GB
Installed Products
Product Names
Oracle Database 11g 11.2.0.4.0
Java Development Kit 1.5.0.51.10
Installer SDK Component 11.2.0.4.0
Oracle One-Off Patch Installer 11.2.0.3.4
Oracle Universal Installer 11.2.0.4.0
Oracle USM Deconfiguration 11.2.0.4.0
Oracle Configuration Manager Deconfiguration 10.3.1.0.0
Oracle DBCA Deconfiguration 11.2.0.4.0
Oracle RAC Deconfiguration 11.2.0.4.0
Oracle Database Deconfiguration 11.2.0.4.0
Oracle Configuration Manager Client 10.3.2.1.0
Oracle Configuration Manager 10.3.8.1.0
Oracle ODBC Driverfor Instant Client 11.2.0.4.0
LDAP Required Support Files 11.2.0.4.0
SSL Required Support Files for InstantClient 11.2.0.4.0
Bali Share 1.1.18.0.0
Oracle Extended Windowing Toolkit 3.4.47.0.0
Oracle JFC Extended Windowing Toolkit 4.2.36.0.0
Oracle Real Application Testing 11.2.0.4.0
Oracle Database Vault J2EE Application 11.2.0.4.0
Oracle Label Security 11.2.0.4.0
Oracle Data Mining RDBMS Files 11.2.0.4.0
Oracle OLAP RDBMS Files 11.2.0.4.0
Oracle OLAP API 11.2.0.4.0
Platform Required Support Files 11.2.0.4.0
Oracle Database Vault option 11.2.0.4.0
Oracle RAC Required Support Files-HAS 11.2.0.4.0
SQL*Plus Required Support Files 11.2.0.4.0
Oracle Display Fonts 9.0.2.0.0
Oracle Ice Browser 5.2.3.6.0
Oracle JDBC Server Support Package 11.2.0.4.0
Oracle SQL Developer 11.2.0.4.0
Oracle Application Express 11.2.0.4.0
XDK Required Support Files 11.2.0.4.0
RDBMS Required Support Files for Instant Client 11.2.0.4.0
SQLJ Runtime 11.2.0.4.0
Database Workspace Manager 11.2.0.4.0
RDBMS Required Support Files Runtime 11.2.0.4.0
Oracle Globalization Support 11.2.0.4.0
Exadata Storage Server 11.2.0.1.0
Provisioning Advisor Framework 10.2.0.4.3
Enterprise Manager Database Plugin -- Repository Support 11.2.0.4.0
Enterprise Manager Repository Core Files 10.2.0.4.5
Enterprise Manager Database Plugin -- Agent Support 11.2.0.4.0
Enterprise Manager Grid Control Core Files 10.2.0.4.5
Enterprise Manager Common Core Files 10.2.0.4.5
Enterprise Manager Agent Core Files 10.2.0.4.5
RDBMS Required Support Files 11.2.0.4.0
regexp 2.1.9.0.0
Agent Required Support Files 10.2.0.4.5
Oracle 11g Warehouse Builder Required Files 11.2.0.4.0
Oracle Notification Service (eONS) 11.2.0.4.0
Oracle Text Required Support Files 11.2.0.4.0
Parser Generator Required Support Files 11.2.0.4.0
Oracle Database 11g Multimedia Files 11.2.0.4.0
Oracle Multimedia Java Advanced Imaging 11.2.0.4.0
Oracle Multimedia Annotator 11.2.0.4.0
Oracle JDBC/OCI Instant Client 11.2.0.4.0
Oracle Multimedia Locator RDBMS Files 11.2.0.4.0
Precompiler Required Support Files 11.2.0.4.0
Oracle Core Required Support Files 11.2.0.4.0
Sample Schema Data 11.2.0.4.0
Oracle Starter Database 11.2.0.4.0
Oracle Message Gateway Common Files 11.2.0.4.0
Oracle XML Query 11.2.0.4.0
XML Parser for Oracle JVM 11.2.0.4.0
Oracle Help For Java 4.2.9.0.0
Installation Plugin Files 11.2.0.4.0
Enterprise Manager Common Files 10.2.0.4.5
Expat libraries 2.0.1.0.1
Deinstallation Tool 11.2.0.4.0
Oracle Quality of Service Management (Client) 11.2.0.4.0
Perl Modules 5.10.0.0.1
JAccelerator (COMPANION) 11.2.0.4.0
Oracle Containers for Java 11.2.0.4.0
Perl Interpreter 5.10.0.0.2
Oracle Net Required Support Files 11.2.0.4.0
Secure Socket Layer 11.2.0.4.0
Oracle Universal Connection Pool 11.2.0.4.0
Oracle JDBC/THIN Interfaces 11.2.0.4.0
Oracle Multimedia Client Option 11.2.0.4.0
Oracle Java Client 11.2.0.4.0
Character Set Migration Utility 11.2.0.4.0
Oracle Code Editor 1.2.1.0.0I
PL/SQL Embedded Gateway 11.2.0.4.0
OLAP SQL Scripts 11.2.0.4.0
Database SQL Scripts 11.2.0.4.0
Oracle Locale Builder 11.2.0.4.0
Oracle Globalization Support 11.2.0.4.0
SQL*Plus Files for Instant Client 11.2.0.4.0
Required Support Files 11.2.0.4.0
Oracle Database User Interface 2.2.13.0.0
Oracle ODBC Driver 11.2.0.4.0
Oracle Notification Service 11.2.0.3.0
XML Parser for Java 11.2.0.4.0
Oracle Security Developer Tools 11.2.0.4.0
Oracle Wallet Manager 11.2.0.4.0
Cluster Verification Utility Common Files 11.2.0.4.0
Oracle Clusterware RDBMS Files 11.2.0.4.0
Oracle UIX 2.2.24.6.0
Enterprise Manager plugin Common Files 11.2.0.4.0
HAS Common Files 11.2.0.4.0
Precompiler Common Files 11.2.0.4.0
Installation Common Files 11.2.0.4.0
Oracle Help for the Web 2.0.14.0.0
Oracle LDAP administration 11.2.0.4.0
Buildtools Common Files 11.2.0.4.0
Assistant Common Files 11.2.0.4.0
Oracle Recovery Manager 11.2.0.4.0
PL/SQL 11.2.0.4.0
Generic Connectivity Common Files 11.2.0.4.0
Oracle Database Gateway for ODBC 11.2.0.4.0
Oracle Programmer 11.2.0.4.0
Oracle Database Utilities 11.2.0.4.0
Enterprise Manager Agent 10.2.0.4.5
SQL*Plus 11.2.0.4.0
Oracle Netca Client 11.2.0.4.0
Oracle Multimedia Locator 11.2.0.4.0
Oracle Call Interface (OCI) 11.2.0.4.0
Oracle Multimedia 11.2.0.4.0
Oracle Net 11.2.0.4.0
Oracle XML Development Kit 11.2.0.4.0
Oracle Internet Directory Client 11.2.0.4.0
Database Configuration and Upgrade Assistants 11.2.0.4.0
Oracle JVM 11.2.0.4.0
Oracle Advanced Security 11.2.0.4.0
Oracle Net Listener 11.2.0.4.0
Oracle Enterprise Manager Console DB 11.2.0.4.0
HAS Files for DB 11.2.0.4.0
Oracle Text 11.2.0.4.0
Oracle Net Services 11.2.0.4.0
Oracle Database 11g 11.2.0.4.0
Oracle OLAP 11.2.0.4.0
Oracle Spatial 11.2.0.4.0
Oracle Partitioning 11.2.0.4.0
Enterprise Edition Options 11.2.0.4.0
-----------------------------------------------------------------------------
Instantiating scripts for add node (Wednesday, January 16, 2019 4:32:37 PM CST)
. 1% Done.
Instantiation of add node scripts completeCopying to remote nodes (Wednesday, January 16, 2019 4:32:44 PM CST)
............................................................................................... 96% Done.
Home copied to new nodesSaving inventory on nodes (Wednesday, January 16, 2019 4:40:53 PM CST)
. 100% Done.
Save inventory complete
WARNING:
The following configuration scripts need to be executed as the "root" user in each new cluster node. Each script in the list below is followed by a list of nodes.
/u01/app/oracle/product/11.2.0/dbhome_1/root.sh #On nodes rac3,rac4
To execute the configuration scripts:
1. Open a terminal window
2. Log in as "root"
3. Run the scripts in each cluster node
The Cluster Node Addition of /u01/app/oracle/product/11.2.0/dbhome_1 was successful.
Please check '/tmp/silentInstall.log' for more details.
根据上面英文提示，需要以root用户在节点rac3和节点rac4上按顺序执行脚本：
/u01/app/oracle/product/11.2.0/dbhome_1/root.sh4、扩展数据库实例
在节点rac1上以oracle用户调用dbca，安装过程如下：
按照添加rac3的相同步骤完成rac4的安装。
- 扩展后检查
查看实例状态：
查看集群状态：
[[email protected] ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
NAME TARGET STATE SERVER STATE_DETAILS
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.CRS.dg
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.DATA.dg
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.LISTENER.lsnr
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.asm
ONLINE ONLINE rac1 Started
ONLINE ONLINE rac2 Started
ONLINE ONLINE rac3 Started
ONLINE ONLINE rac4 Started
ora.gsd
OFFLINE OFFLINE rac1
OFFLINE OFFLINE rac2
OFFLINE OFFLINE rac3
OFFLINE OFFLINE rac4
ora.net1.network
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.ons
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
ora.registry.acfs
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ONLINE ONLINE rac3
ONLINE ONLINE rac4
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE rac2
ora.cvu
1 ONLINE ONLINE rac2
ora.oc4j
1 ONLINE ONLINE rac2
ora.rac1.vip
1 ONLINE ONLINE rac1
ora.rac2.vip
1 ONLINE ONLINE rac2
ora.rac3.vip
1 ONLINE ONLINE rac3
ora.rac4.vip
1 ONLINE ONLINE rac4
ora.racdb.db
1 ONLINE ONLINE rac1 Open
2 ONLINE ONLINE rac2 Open
3 ONLINE ONLINE rac3 Open
4 ONLINE ONLINE rac4 Open
ora.scan1.vip
1 ONLINE ONLINE rac2
检查所有节点的asm alert日志、db alert日志，看是否有异常。
如果所有日志都正常的话，就意味着添加RAC节点的操作成功完成。
参考博文：http://www.cnxdug.org/?p=2506