RE: shared memory processes and oracle instances

I have also used 'oradebug ipc' in the past. But, before I knew that I tried a different approach. There were 1 production and 2 other instances on the same box. Accidentally one of the 2 non-production got aborted accidentally. The 'ipcs -ma' still showed 3 instances. In order to startup the aborted instance I had to first cleanup the shared memory process (using ipcrm). My approach was to find the instance startup time for the instances already up, compare it with the last field CTIME (ipcs -ma). These were not exactly same, but close enough to identify the running instances (and thus, idenitfying the aborted instance)

But, surely 'oradebug ipc' is the answer. I am, however, not sure what happens when there are more than 1 shared memory process per Oracle instance when issuing a 'ipcs -ma'.

• Deepak
  • "Deshpande, Kirti" <Kirti.Deshpande_at_gtedc.gte.com> wrote:
    > Hi Walt,
    > Thanks for the info.
    > I did not know that..
    > Works for Oracle 7.3.4 as well. Displays both Shared
    > Memory and Semaphore
    > related info.
    > In 8.0.6 it creates a trace file (in udump dest) for
    > Shared Memory
    > information but the Semaphores info is displayed on
    > the screen. I was using
    > HP-UX 10.20 (for 7.3.4) and HP-UX 11.0 (for 8.0.6).
    >
    >
    > - Kirti
    >
    > > -----Original Message-----
    > > From: Weaver, Walt [SMTP:wweaver_at_rightnowtech.com]
    > > Sent: Tuesday, June 06, 2000 10:55 AM
    > > To: Multiple recipients of list ORACLE-L
    > > Subject: RE: shared memory processes and oracle
    > instances
    > >
    > > Couldn't you do this in Oracle 8 using "oradebug
    > ipc"? It should give you
    > > the shared memory id associated with the SID...
    > >
    > > --Walt Weaver
    > > Bozeman, Montana, USA
    > >
    > > -----Original Message-----
    > > Sent: Tuesday, June 06, 2000 8:11 AM
    > > To: Multiple recipients of list ORACLE-L
    > >
    > >
    > > Hi,
    > > Here is how to do this with 7.3.x databases...
    > >
    > > Get the o/p from 'ipcs -m' command as below:
    > > IPC status from /dev/kmem as of Tue Jun 6
    > 07:40:40 2000
    > > T ID KEY MODE OWNER
    > GROUP
    > > Shared Memory:
    > > m 6309 0x7965c84f --rw-r----- oracle
    > dba
    > > m 6310 0x7965c9a3 --rw-r----- oracle
    > dba
    > > m 7711 0x79775045 --rw-r----- oracle
    > dba
    > > m 13312 0x796b4eb3 --rw-r----- oracle
    > dba
    > > m 14013 0x7968cfb8 --rw-rw---- oracle
    > dba
    > > m 20314 0x790a4eea --rw-r----- oracle
    > dba
    > > m 15 0x79614f93 --rw-r----- oracle
    > dba
    > > m 16 0x79624f8b --rw-r----- oracle
    > dba
    > > m 17 0x7908cf8f --rw-r----- oracle
    > dba
    > > m 8418 0x796ecf27 --rw-rw---- oracle
    > dba
    > > m 19 0x7908cefa --rw-r----- oracle
    > dba
    > > m 20 0x7962cf4b --rw-r----- oracle
    > dba
    > > m 21 0x790a4f37 --rw-r----- oracle
    > dba
    > >
    > > Then, use 'od -d sgadef<SID>.dbf' command for the
    > SID in question to get a
    > > display as below.
    > > My SID is YPPD...
    > >
    > > df2hp019 [YPPD]: od -d sgadefYPPD.dbf
    > > 0000000 00000 00001 00000 00432 57287 57344 65535
    > 65535
    > > 0000020 00312 24576 00000 00000 00000 08418 65535
    > 65535
    > > 0000040 31086 53031 47470 53031 00000 00001 00000
    > 01948
    > > 0000060 65535 65535 65535 65535 65535 65535 65535
    > 65535
    > > *
    > > 0000124
    > > df2hp019 [YPPD]:
    > >
    > > Look across the 2nd line (starting with 0000020)
    > and get the value in col
    > > #
    > > 3 from the far right. In my example, it is 08418.
    > It is the Shared Memory
    > > ID, my SID (YPPD) is using. Look for it in the
    > display from 'ipcs -ma' to
    > > get other related information.
    > >
    > > However, this process won't work with Oracle 8.x
    > datatabases, as file
    > > sgadef.dbf became obsolete. I have not found any
    > way, yet, to associate
    > > shared memory segment id to the sid.
    > > If anyone else know, please post the answer...
    > >
    > > Here is what is in sgadef file for Oracle 8.0.6
    > databases when I viewed it
    > > with 'cat' command:
    > >
    > > df2hp105 [IWHP]: cat sgadefIWHP.dbf
    > > This file is now obsolete. It will be removed in
    > a future release.
    > > To determine whether an instance is up, you should
    > check for the
    > > existence of the PMON process associated with the
    > instance.
    > >
    > >
    > > Hope this is what you were after...
    > >
    > > - Kirti
    > >
    > >
    > > > -----Original Message-----
    > > > From: ALEMU Abiy
    > [SMTP:abiy.alemu_at_criltechnology.com]
    > > > Sent: Tuesday, June 06, 2000 1:24 AM
    > > > To: Multiple recipients of list ORACLE-L
    > > > Subject: shared memory processes and oracle
    > instances
    > > >
    > > > I have several instances running and I would
    > like to know which shared
    > > > process correspond to a given instance from
    > those that I see with the
    > > > command ipcs. Is there any way to associate
    > these processes with the
    > > > instances (an id number to designate) ?
    > > > --
    > > > Author: ALEMU Abiy
    > > > INET: abiy.alemu_at_criltechnology.com
    > > >
    > > >
    > >
    > --
    > Author: Deshpande, Kirti
    > INET: Kirti.Deshpande_at_gtedc.gte.com
    >
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