关于ocssd进程的三言两语

1.OCSSD有的文档称为Oracle Cluster Synchronization Service Daemon，有的称为Oracle Cluster Support Services daemon，文档一致性问题而已。

2.The OCSSD performs some of the clusterware functions on UNIX-based systems.

3.ocssd负责实现数据库的instanc和ASM的instance之间的通讯

4.the ocssd installation procedure ($ORACLE_HOME/bin/localconfig add) adds an entry to inittab:

h1:35:respawn:/etc/init.d/init.cssd run >/dev/null 2>&1

5."ASM instace启动以后，通过gmon进程和osccd通信，将ASM的一些信息告诉给ocssd，而数据库则从ocssd获得这些信息，也就是说，ocssd是ASM Instance和Database之间的纽带"

参考链接:
http://www.ningoo.net/html/2008/how_an_asm_diskgroup_found_by_oracle_database.html
http://frits.homelinux.com/wordpress/?p=34

Quote more:

After the ocssd is being started, it opens up a number of filedescriptors:
-some message files:
-- $ORACLE_HOME/srvm/mesg/procus.msb
-- $ORACLE_HOME/css/mesg/clssus.msb
-- $ORACLE_HOME/has/mesg/clsdus.msb
-some logging:
-- $ORACLE_HOME/log/hostname/cssd/cssdOUT.log (3 times)
- $ORACLE_HOME/log/hostname/cssd/ocssd.log
- $ORACLE_HOME/log/hostname/alertpmoracle.log
-the cluster registry disk, which can be file on the local (non-cluster) filesystem because the ocssd is the only process/daemon which uses it:
- $ORACLE_HOME/cdata/localhost/local.ocr
-some sockets on the local filesystem:
- /var/tmp/.oracle/shostnameDBG_CSSD
- /var/tmp/.oracle/sOracle_CSS_LclLstnr_localhost_0
- /var/tmp/.oracle/sOCSSD_LL_hostname_
- /var/tmp/.oracle/sOCSSD_LL_hostname_localhost
-and some network sockets:
- UDP [::1]:1027
- UDP [::1]:1028
- UDP [::1]:1029
- UDP [::1]:1030
- TCP 127.0.0.1:31144
- TCP 127.0.0.1:8986

(this information is found in /proc/pid/fd and using 'lsof')