关于NIS 伺服器的概念&&stopsrc -s ypbind

现象：在安装director 6.3.2时，DB2安装 错误：
   Menotr查看log后执行：
部分的log如下：

hu Aug  9 03:57:32 CDT 2012
+=============================================================================+
[Thu Aug  9 03:57:37 CDT 2012]: Start of product installation.
+=============================================================================+
PRE_INSTALL_CHECKS : 0
PortNumber : 8401
SecurePortNumber : 8402
AGENT_MANAGER_PORT : 20000
MIGRATE_DATA : 1
/usr/bin/lslpp: 0504-132  Fileset DirectorServer not installed.
[Thu Aug  9 03:57:38 CDT 2012]: isMigrationTriggered: 0.
[Thu Aug  9 03:57:38 CDT 2012]: localIP: 10.10.18.239
/mnt/SysDir/server
[Thu Aug  9 03:57:45 CDT 2012]: Return code of db2prereqcheck: 0.
[Thu Aug  9 03:57:45 CDT 2012]: Managed DB2 is supported and its prerequisites are met.
DB_INST_TYPE : 1
DB_DATAPATH : /home/dirinst1
[Thu Aug  9 03:57:45 CDT 2012]: DB_DATAPATH_FS : /home
DB_PWD : default.
DB_INSTANCEPATH : .
DB_SERVER : localhost
DB_PORT : default
[Thu Aug  9 03:57:45 CDT 2012]: imagePath : /mnt/SysDir/server
[Thu Aug  9 03:57:46 CDT 2012]: Trying to enlarge space of filesystem / to 128M
Filesystem size changed to 1114112
[Thu Aug  9 03:57:48 CDT 2012]: Trying to enlarge space of filesystem /usr to 512M
Filesystem size changed to 11141120
[Thu Aug  9 03:57:52 CDT 2012]: INST_PHASE:=========== Managed DB2 install begins ===============
3004-687 User "dirinst1" does not exist.
The system call does not exist on this system.
Log file:  /tmp/installdb2.log
Check for availability of port  50010
Installing 64-bit DB2
DBI1191I  db2setup is installing and configuring DB2 according to the
response file provided. Please wait.

iocp0 A minor error occurred while installing "DB2 Enterprise Server Edition " on
this computer. Some features may not function correctly.

For more information see the DB2 installation log at "/tmp/db2setup.log".
DB2 failed to install.
error rc 17
Log file: /tmp/uninstalldb2.log
DB2 Instance: dirinst1
Dropping DIRDB, stopping DB2 and terminating DB2
3004-500 User "dirinst1" does not exist.
DBI1291E  The instance dirinst1 was not found in the instance
list.

Explanation:

The specified instance was not found in the instance list.

User response:

Verify that the list of instances as reported by the "db2ilist" command
is correct. Retry the command with a valid instance name.

DBI1079I  Output is saved in the log file /tmp/db2idrop.log.3408176.

#ps -ef|grep ypbind
#stopsrc -s  ypbind

注意是stopsrc 停止这个服务，而不是杀死这个服务，否则因为有一个daemon进程会一直的创建新的
ypbind 进程，所以不要傻傻的要把这个服务给杀死。。。

然后重试安装DB2顺利安装：
ypbind 服务是NIS 提供的服务。。
下面是鸟哥的主页关于NIS的介绍：
http://

ypbind 是 NIS提供的服务。。
下面是IBM iNFORMATION  Center 提供的：
%2Fcom.ibm.aix.cmds%2Fdoc%2Faixcmds6%2Fypbind.htm

AIX 6.1 information > Commands > y
ypbind Daemon
Purpose

Enables client processes to bind, or connect, to an NIS server.
Syntax

/usr/lib/netsvc/yp/ypbind [ -s -ypset -ypsetme ]
Description

The ypbind daemon binds, or connects, processes on a Network Information Services (NIS) client to services on an NIS server. This daemon, which runs on every NIS client, is started and stopped by the following System Resource Controller (SRC) commands:

startsrc -s ypbind

stopsrc -s ypbind

When a client requests information from a Network Information Services (NIS) map, the ypbind daemon broadcasts on the network for a server. When the server responds, it gives the daemon the Internet address and port number of a host. This is the host that provides the information the client is seeking. The ypbind daemon stores this address information in the /var/yp/binding directory using a file name of domainname.version. Then, the next time the client wants to access an NIS map, the client's ypbind daemon refers to the addresses in the domainname.version file.

The ypbind daemon can maintain bindings to several domains and their servers -ypsetme simultaneously. The default domain is the one specified by the domainname command at startup time.
Notes:

If a domain becomes unbound (usually when the server crashes or is overloaded), the ypbind daemon broadcasts again to find another server.
To force a client to bind to a specific server, use the ypset command.
To find out which server a client is bound to, use the ypwhich command.
If the /var/yp/binding/domainname/ypservers file exists, ypbind will attempt to contact the servers listed in that file before broadcasting. The file should contain a list of server IP addresses, one per line.
By default, the NIS client will wait indefinitely for the NIS server, during which time, logins to the client system are not possible. It is possible, however, to limit the length of this wait. If the YPBIND_MAXWAIT environment variable is set (usually in /etc/environment) before the ypbind daemon is started, this value (in seconds) will limit the amount of time the NIS client will wait for the NIS server. If this limit is exceeded, the client behaves as if NIS were unavailable and continues using local files. This will allow local logins, such as root.
If a domain becomes unbound and it is listed in the /var/yp/binding/domainnanme/ypservers file, by default ypbind daemon attempts to contact the server that is currently down; however, if the YPBIND_SKIP environment variable is set to 1 (usually set in the /etc/environment file) before the ypbind daemon is started, the server that is currently down will not be contacted again.

Flags
-s 	Runs the ypbind daemon in a secure mode on privileged communications ports.
-ypset 	Indicates the local host accepts ypset commands from local or remote hosts.
-ypsetme 	Indicates that the local host accepts ypset commands only from the local host. This flag overrides the -ypset flag if both are specified.
Notes:

If neither the -ypset or -ypsetme flags are specified, the local host rejects all ypset commands from all hosts. This is the most secure mode because the NIS server cannot change.
If neither the -ypset or -ypsetme flags are specified, the local host rejects all ypset commands from all hosts. This is the most secure mode because the NIS server cannot change. However, if no NIS servers exist on the networks directly connected to the client machine, then the -ypsetme flag must be used and the NIS server should be specified with the ypset command.

Files
/var/yp/binding directory 	Contains Internet addresses and port numbers for NIS servers.
/var/yp/binding/domainname/ypservers 	Contains a list of internet addresses, one per line, of servers to attempt to contact before broadcasting.
domainname.version 	Binary file that contains the address and port number of the current NIS server.

NIS 的由來與功能

在一個大型的網域當中，如果有多部 Linux 主機，萬一要每部主機都需要設定相同的帳號與密碼時，你該怎麼辦？複製 /etc/passwd ？應該沒有這麼呆吧？如果能夠有一部帳號主控伺服器來管理網域中所有主機的帳號， 當其他的主機有使用者登入的需求時，才到這部主控伺服器上面要求相關的帳號、密碼等使用者資訊， 如此一來，如果想要增加、修改、刪除使用者資料，只要到這部主控伺服器上面處理即可， 這樣就能夠降低重複設定使用者帳號的步驟了。

這樣的功能有很多的伺服器軟體可以達成，這裡我們要介紹的則是 Network Information Services (NIS server) 這個伺服器軟體喔！底下就先來談一談這個 NIS 的相關功能吧！