Is my Oracle instance still running?

My Oracle 9i database is running well on Linux for a while (several days), then it seems to go down. I could not connect to the database using sqlplus. If I restart the database, the problem will be solved temporarily (only for several days). Then the problem repeats.

dvserver% sqlplus system/mypasswd_at_MYDB

SQL*Plus: Release 9.2.0.4.0 - Production on Sun Oct 24 10:57:51 2004

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist Linux Error: 2: No such file or directory

My questions are:
1). Is my Oracle Instance still running? 2). What are the possible reasons and how to solve the problem?

When I tried to check the oracle instance , I get the following result:

dvserver:/oracle# ps -ef | grep oracle
oracle 12176 1 0 Oct07 ? 00:11:59
/oracle/home/bin/tnslsnr LISTENER -inherit
oracle 12185 1 0 Oct07 ? 00:00:00 /bin/sh
/oracle/home/bin/dbsnmpwd

oracle 12188 12185 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12190 12188 0 Oct07 ? 00:00:25
/oracle/home/bin/dbsnmp

oracle 12191 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12195 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12196 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12197 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12198 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12199 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12200 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12201 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12202 12190 0 Oct07 ? 00:00:02
/oracle/home/bin/dbsnmp

oracle 12203 12190 0 Oct07 ? 00:00:59
/oracle/home/bin/dbsnmp

oracle 12204 12190 0 Oct07 ? 00:02:40
/oracle/home/bin/dbsnmp

oracle 12205 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12206 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12207 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle 12212 12190 0 Oct07 ? 00:00:00
/oracle/home/bin/dbsnmp

oracle   25851 25839  0 Oct21 pts/1    00:00:00 zsh
oracle    1051     1  0 10:57 ?        00:00:00 oracleMYDB (LOCAL=NO)
root      1157 32649  0 11:01 pts/2    00:00:00 grep oracle

Thanks! Received on Sun Oct 24 2004 - 13:36:55 CDT