Alert log in 11gR2

Oracle 11g introduce new tool/utility called ADRCI known as ADR command line tool.
This tool allow user to interact with ADR ,check alert log, check health monitor(HM) status ,

Package incident and problem information into a zip file for send to Oracle Support. Etc.

No username/password need to log in to ADRCI, ADRCI interact with file system and ADR data is secured only by operating system permissions on the ADR directories.

$adrci
adrci> set editor vi
adrci> show alert ( it will open alert in vi editor )
adrci> show alert -tail ( Similar to Unix tail command )
adrci> show alert -tail 200 ( Similar to Unix Command tail -200 )
adrci> show alert -tail -f ( Similar to Unix command tail -f )

adrci> show alert -tail 100 -f ( Similar to tail -100f )


Too list all the "ORA-" error run following command

$adrci
adrci> show alert -P "MESSAGE_TEXT LIKE '%ORA-%'"

>

In 11g alert file is saved in 2 location, one is in alert directory ( in XML format log.xml ) and
old style alert file in trace directory. Both these directory reside inside ADR HOME. ADR (Automatic Diagnostic Repository ) is a file system based directory structure outside of the database, S
o you can have access of diagnostic data even database is down.

New initialization parameter DIAGNOSTIC_DEST decide where to store ADR data ( i.e diagnostic data). In oracle 11g parameter background_dump_dest, core_dump_dest, user_dump_dest is replaced by DIAGNOSTIC_DEST. Even you set background_dump_dest, core_dump_dest, user_dump_dest it not going to used i.e. 11g ignore these parameters.

SQL> show parameter diagnostic_dest

NAME TYPE VALUE
--------------- --------------------------- -------------------------

diagnostic_dest string /u01/app/oracle