weird problem when login in using sqlplus from non oracle unix account

[James A. Donovan · Accepted solution]

From a Metalink Forums thread
search keys: ORA-27101 symbolic links

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RDBMS Version: 8.1.7
Operating System and Version: Windows 2000
Error Number (if applicable): ORA-1034, ORA-27101
Product (i.e. SQL*Loader, Import, etc.): sqlplus
Product Version:

shared memory realm error occuring only when connect to network.

Interesting problem when trying to connect to a Local database NOT connected to the network, connection occurs fine.
HOWEVER, connected to the network the errors
ORA-1034 - Oracle not available and
ORA-27101 - shared memory realm does not exist; appear.

The user profile does not change as the local profile is used.
Listener.ora, sqlnet.ora and tnsnames.ora files do not change.

Any ideas?

Thank you in advance.
Craig.
crb@amsa.gov.au





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From: Oracle, Harm Joris ten Napel 22-Nov-01 09:31
Subject: Re : shared memory realm error occuring only when connect to network.


Hi,

yes, every once in a while this little lesson needs to be thaught,
once it's understood enlightment follows quickly:

When you start an oracle database a key for the shared memory segment
is calculated based on the contents of ORACLE_SID and ORACLE_HOME,
call it a hash value. When you try to connert later, your server
process needs to find the shared memory segment so it does that by
taking your ORACLE_SID and ORACLE_HOME and calculates the hash value,
when at the designated key no SGA is present you get the ora-27101.

Note that when the contents of ORACLE_HOME differ, although it may
point to the same physical location on disk, the hash value will be
different, this is the main reason why Oracle discourages the use of
symbolic links: you can but you have to be consequent.

When attemting to connect over sqlnet, the ORACLE_HOME and ORACLE_SID
from the listener.ora are used, in your case this must differ from
what ORACLE_HOME and ORACLE_SID where when you first started your
database (especially trailing slashes '/' in your listener.ora).

P.S. there is a slight change (rare) that the server process spawned
by the listener cannot access the SGA because of permission problems,
this usually happens when having more users than just oracle that own
software on your system.

greetings,

Harm







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From: Oracle, Gina Thunder 26-Nov-01 15:53
Subject: Re : shared memory realm error occuring only when connect to network.


Thank you, Harm. Also note that there is a bug with the startup: #1522966. The workaround is to comment out the SQLNET.AUTHENTICATION_SERVICES= (NTS) in your $ORACLE_HOME/network/admin/sqlnet.ora file. There is a fix for this problem within the 8.1.7.0.1. patchset. To find this patch, you will need to use the following method:

=> Patches
=> Click top link to take you to the "(old) patch download screen"
=> Select the following from the drop down menus:
-All Products
-MS Windows NT

=>Then do a 'find' on the page for patch: 1522966

Gina
Oracle Support Services

[James A. Donovan]

also see Metalink Note:122183.1

...

[Henrique Silva_3]

Jim, thanks, this makes SENSE now !!!! wow !!

so, it is not so transparent to play with binaries and oracle homes !!!

Looking at my listener.ora file, I had the ORACLE_HOME set there as 8.1.7_64 !!! Corrected that and restarted the listener with the proper ORACLE_HOME !!!

I LEARNED SOMETHING NEW TODAY !!!

Thanks a lot, a really appreciate it. I feel that forums like this, really helps everyone understand this beast !! :-)

Henrique