lk[SID] files

Tonight while waiting for the imp to finish, I am wondering what those lk<sid> files at $ORACLE_HOME/dbs are used for? As usual Google is my solution.

-rw-rw---- 1 oracle dba 24 Jun 7 03:43 lkGENARCHP

-rw-rw---- 1 oracle dba 24 May 26 23:14 lkGENP

-rw-rw---- 1 oracle dba 24 May 4 12:28 lkGENQA

-rw-rw---- 1 oracle dba 24 Jan 18 2004 lkNBDWSP

-rw-rw---- 1 oracle dba 24 Apr 9 15:04 lkTESTDB1

From : http://www.freelists.org/archives/oracle-l/09-2004/msg00372.html

It is a lock file.

When a database starts, one of the background processes locks the file 

(creating it first if necessary). An attempt to start up the database again 

will fail because the old background process holds the lock,

preventing the new background process from getting it.

Garry Gillies