First, propose problems
In the actual process, sometimes we will encounter such problems when you try to start the database with Startup to start an error in ORA-01102. We can switch to Oracle's users under UNIX, and Oerr ORA 1102 will see the short description of 1102, as follows:
RP2 $ [/ home / ora2] Oerr ORA 1102
01102, 00000, "Cannot Mount Database In Exclusive Mode"
// * Cause: Some Other Instance Has The Database Mounted Exclusive or Shared.
// * action: shutdown other instance or mount in a Compatible Mode
I have seen this 1102 short explanation you must be a bit confused because it has some misleading. I will analyze the causes of the problem and give a solution.
Second, analyze the reason
When you start the database 1102 error, the previous database's Down operation is generally not normal, or because some exceptions remain some memory structure in the operating system, a few processes such as PMON still have any reason for Oracle. Mistaken is that instance is still running, so the library has not started, specifically, the general reasons have the following:
1, PMON, SMON, LWGW and DBWR These background processes still exist
2, the shared memory opened by Oracle is not released
3, "LK
Third, solve the problem
I know the reason, it is simple to solve it, the way is as follows:
1. Look at "LK
Oracle $ CD $ ORACLE_HOME / DBS
Oracle $ LS -L SGADEF
If there is a delete it
Oracle $ RM SGADEF
Oracle $ LS -L LK
If there is a delete it
Oracle $ RM LK
2, see if there is a background process exists
Oracle $ PS-EF | GREP ORA_ | GREP $ ORACLE_SID
If there is a residual residue of these background processes, kill -9 offs it
Oracle $ KILL -9 PID
3. Look at Oracle's shared memory segment and Semaphores still still exist.
1) Clear shared memory segment
Oracle $ ipcs -m - Show, watching Owner is Oracle User
Oracle $ ipcrm -m
2) Qing signal set
Oracle $ ipcs -s - Show, watch Owner is Oracle user
Oracle $ ipcrm -s
Fourth, there should be no problem, try again ^ - ^
