Re: ORA-07307: sms1sg: shmat error, unable to attach sga

From: Mary Travis <Mary.B.Travis_at_bridge.bellsouth.com>
Date: 1997/05/21
Message-ID: <5lv9uo$p7c@atglab10.atglab.bls.com>#1/1

Steve Radford <SRadford_at_Rational.com> wrote:

>{
>ORA-07307: sms1sg: shmat error, unable to attach sga.
>ORA-01034: ORACLE not available
>}

Steve,
This looks a little closer to the mark...

Article-ID:         <PR:45482.1>
Subject:            ARTICLE: ALERT: ORACLE TRACE IS ENABLED BY DEFAULT
Circulation:         ** PUBLIC **


Affected Platforms:       - Generic: not platform specific

Affected Products: Oracle7 Server

Keywords: ORACLE;TRACE;ENABLED;EPC_DISABLED

Oracle Trace is Enabled by default

Versions Affected

Oracle Trace was introduced in Oracle7 release: 7.3.2.1 It is enabled by default in many 7.3.2 and 7.3.3 releases.

Platforms Affected

Oracle Trace is enabled by default on most Unix platforms. Oracle Trace is NOT included with Windows NT 7.3.2 releases.

Description

Oracle Trace is a new, common tracing mechanism which is automatically

enabled in Oracle 7.3.2 on most platforms. Products instrumented with

Oracle Trace include:

        SQL*Net v2.3
        Oracle Server 7.3
        Oracle Forms 5.0

Unless specific actions are taken Oracle Trace may be enabled when it is

not required.

Likelihood of Occurrence

On Unix platforms it is quite likely there is some impact from Oracle

Trace being enabled, even if this is only a small performance degradation.

Please Note: Oracle trace works well if correctly configured and used

                 in a targeted manner. The problems described here can
                 occur when Oracle Trace is not configured and is
widely
                 enabled .

Possible Symptoms

Widespread use of Oracle Trace can have a number of apparently mysterious

side effects including:

Very slow database connect times
Poor Oracle response times
High disk space usage by the file 'process.dat'
Oracle errors attaching to the SGA, such as ORA 7307 or ORA 7337
Protocol errors (such as TNS 12164) errors from SQL*Net
Sessions aborting or hanging when connecting to the instance
Bus errors and/or core dumps from SQLPLUS or SVRMGRL
Trace files being written to the default USER_DUMP_DEST rather than the actual setting of USER_DUMP_DEST
Zero length trace files

Workaround / Patches

There are no patches available.

The workaround is to set the parameter EPC_DISABLED to TRUE in the users environment.

Workaround on Unix:

Shut down all 7.3 databases.
Reinitialise the Oracle Trace output files:

                cd $ORACLE_HOME/otrace/admin
                rm -f process.dat regid.dat
                otrccref

      3. Set the environment variable EPC_DISABLED to TRUE for all
users.
         If you have a common environment script where ORACLE_HOME is
set
         this is probably the best place to set this.
         Eg: In a Bourne script:
                EPC_DISABLED=TRUE; export EPC_DISABLED

             In the C-Shell:
                setenv EPC_DISABLED TRUE

      4. Make sure any SQL*Net connections have EPC_DISABLED in the
         environment. To ensure this you can modify the
'SID_LIST_listener'
         clause in the 'listener.ora' file and add:

                (ENVS='EPC_DISABLED=TRUE')

         to the SID_DESC for each 7.3 database. Add the entry AFTER
the
         (ORACLE_HOME=...) clause.

         Eg:
            SID_LIST_LISTENER=
             (SID_LIST=
              (SID_DESC=
                (SID_NAME=DB1)

(ORACLE_HOME=/oracle/OFA_base/app/oracle/product/7.3.2)
                (ENVS='EPC_DISABLED=TRUE')
              )
              (SID_DESC=
                (SID_NAME=DB2)

(ORACLE_HOME=/oracle/OFA_base/app/oracle/product/7.3.2)
                (ENVS='EPC_DISABLED=TRUE')
              )
            )

        5. Restart and databases and SQL*Net listeners.

References

    Connection/query time is slow                       <PR:1020763.6>
    Slow connect times                                    <Bug:443047>
    ORA 7307 Unable to attach SGA                         <Bug:374964>
    Server Process hanging                                <Bug:387185>
_______________________________________________________________________________

                                             Oracle WorldWide Customer

Support

Mary Travis
BellSouth Telecommunications
email: Mary.B.Travis_at_bridge.bellsouth.com Received on Wed May 21 1997 - 00:00:00 CDT