SYSRESV Details
==================
This provide facility to get details of mapped shared memory with oracle instances.
This utility can be used to both identify which shared memory segments belong to which instances and eliminate any DBA guess work or difficult correlation via alternative mechanism.
sysresv is the utility provided by oracle to manage the shared memory and semaphores used by the oracle SID by that users.
==> Location of SYSRESV executables.
[oracle@ace2oracledb bin]$ pwd
/oracle_home/app/19c/oracle/bin
[oracle@ace2oracledb bin]$
[oracle@ace2oracledb bin]$
[oracle@ace2oracledb bin]$ sysresv
IPC Resources for ORACLE_SID "STDB" :
Maximum shared memory segment size (shmmax): 4398046511104 bytes
Total system shared memory (shmall): 4398046511104 bytes
Total system shared memory count (shmmni): 4096
*********************** Dumping ipcs output ********************
------ Message Queues --------
key msqid owner perms used-bytes messages
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 262144 grid 777 16384 1 dest --------------->>>> dest means " Need to be destroyed"
0x00000000 294913 grid 777 7602176 2 dest
0x0d3effb0 1900546 grid 600 28672 27
0x00000000 524291 grid 777 7602176 2 dest
0x00000000 491524 grid 600 524288 2 dest
0x00000000 1114117 grid 600 524288 2 dest
0x00000000 655366 grid 600 524288 2 dest
0x00000000 1015815 grid 600 16777216 2 dest
0x00000000 2981896 oracle 600 8904704 111
0x00000000 1179657 grid 777 7127040 2 dest
0x00000000 3014666 oracle 600 3372220416 56
0x00000000 3047435 oracle 600 7872512 56
0x8e70e24c 3080204 oracle 600 20480 56
0x00000000 2686990 grid 777 7127040 2 dest
0x00000000 2654223 grid 600 524288 2 dest
------ Semaphore Arrays --------
key semid owner perms nsems
0xf297b4a4 753664 grid 600 124
0xdc546154 1310721 oracle 600 250
0xdc546155 1343490 oracle 600 250
*********************** End of ipcs command dump **************
***************** Dumping Resource Limits(s/h) *****************
core file size 0 KB/UNLIMITED
data seg size UNLIMITED/UNLIMITED
scheduling priority 0 KB/0 KB
file size UNLIMITED/UNLIMITED
pending signals 34 KB/34 KB
max locked memory 128 GB/128 GB
max memory size UNLIMITED/UNLIMITED
open files 64 KB/64 KB
POSIX message queues 800 KB/800 KB
real-time priority 0 KB/0 KB
stack size 32 MB/32 MB
cpu time UNLIMITED/UNLIMITED
max user processes 16 KB/16 KB
virtual memory UNLIMITED/UNLIMITED
file locks UNLIMITED/UNLIMITED
***************** End of Resource Limits Dump ******************
Maximum map count configured per process: 65530
Total /dev/shm size: 3906871296 bytes, used: 671608832 bytes
Shared Memory: >>>>>>>>>>>> Shared memory details
ID KEY
3014666 0x00000000
3047435 0x00000000
2981896 0x00000000
3080204 0x8e70e24c
Semaphores: >>>>>>>>>>>> Semaphores Details
ID KEY
1310721 0xdc546154
1343490 0xdc546155
Oracle Instance alive for sid "STDB"
[oracle@ace2oracledb bin]$
[oracle@ace2oracledb bin]$
=====>>>>
[oracle@ace2oracledb bin]$ sysresv -help
sysresv: invalid option -- 'h'
usage : sysresv [-if] [-d ] [-l sid1 ...]
-i : Prompt before removing ipc resources for each sid
-f : Remove ipc resources silently, oevrrides -i option
-d : List ipc resources for each sid if on
-l sid1 .. : apply sysresv to each sid
Default : sysresv -d on -l $ORACLE_SID
Note : ipc resources will be attempted to be deleted for a
sid only if there is no currently running instance
with that sid.
[oracle@ace2oracledb bin]$
====>>>>>
Examples:
---------
o Instance is not running:
/u02/app/oracle/product/8.1.7> sysresv
IPC Resources for ORACLE_SID "R817" :
Shared Memory
ID KEY
No shared memory segments used
Semaphores:
ID KEY
No semaphore resources used
Oracle Instance not alive for sid "R817"
o Instance is running:
/u03/app/oracle/product/8.1.6> sysresv
IPC Resources for ORACLE_SID "ORCL" :
Shared Memory:
ID KEY
16437 0xe4efa8dc
Semaphores:
ID KEY
12320802 0x09d48346
Oracle Instance alive for sid "ORCL"
o Attempting to remove memory and semphores using sysresv when Oracle
detects an instance is running:
/u03/app/oracle/product/8.1.6> sysresv -f
IPC Resources for ORACLE_SID "ORCL" :
Shared Memory:
ID KEY
16437 0xe4efa8dc
Semaphores:
ID KEY
12320802 0x09d48346
Oracle Instance alive for sid "ORCL"
SYSRESV-005: Warning
Instance maybe alive - aborting remove for sid "ORCL"
o Removing IPC resources:
[Sysresv shows memory and semaphores exist but Oracle determines the
instance is not alive. Cleanup is needed.]
/u03/app/oracle/product/8.1.6> sysresv
IPC Resources for ORACLE_SID "ORCL" :
Shared Memory:
ID KEY
16837 0xe4efa8dc
Semaphores:
ID KEY
12714018 0x09d48346
Oracle Instance not alive for sid "ORCL"
o Removing IPC resources using sysresv:
/u03/app/oracle/product/8.1.6> sysresv -i
IPC Resources for ORACLE_SID "ORCL" :
Shared Memory
ID KEY
No shared memory segments used
Semaphores:
ID KEY
No semaphore resources used
Oracle Instance not alive for sid "ORCL"
Remove ipc resources for sid "ORCL" (y/n)?y
Done removing ipc resources for sid "ORCL"
/u03/app/oracle/product/8.1.6
Verify the resources were removed:
/u03/app/oracle/product/8.1.6> sysresv
IPC Resources for ORACLE_SID "ORCL" :
Shared Memory
ID KEY
No shared memory segments used
Semaphores:
ID KEY
No semaphore resources used
Oracle Instance not alive for sid "ORCL"
o If you need to remove memory segments, and Oracle detects the
instance is alive through sysresv:
% ipcrm -m
Where is the memory id shown in the sysresv output.
Example:
% ipcrm -m 16437
If you need to remove semaphores, and Oracle detects the
instance is alive through sysresv:
% ipcrm -s
where is the semaphore id shown in the sysresv output.
Example:
% ipcrm -s 12320802
References:
===========
Note:115235.1 Resolving ORA-7279 or ORA-27146 errors when starting instance.
Bug:566223
Bug Number 1588021
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