Area Subarea Shmid Stable Addr Actual Addr
5 5 3080200 0x0000005e800000 0x0000005e800000
Subarea size Segment size
0000000000003000 000000003ec00000
Dump of Linux-specific skgm context
sharedmmu 00000001
shareddec 0
used region 0: start 0000000012000000 length 0000000000400000
used region 1: start 0000000020000000 length 000000003ec00000
used region 2: start 00000000af800000 length 0000000010800000
Maximum processes: = 150
Number of semaphores per set: = 154
Semaphores key overhead per set: = 4
User Semaphores per set: = 150
Number of semaphore sets: = 1
Semaphore identifiers: = 1
Semaphore List=
131073
-------------- system semaphore information -------------
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 2883587 root 644 52 2
0x00000000 2916357 root 644 16384 2
0x00000000 2949126 root 644 268 2
0xd3ac6c80 3080200 oracle 660 4096 0
------ Semaphore Arrays --------
key semid owner perms nsems
0x5c23a1bc 131073 oracle 660 154
------ Message Queues --------
key msqid owner perms used-bytes messages
Since we cannot get the semaphore set number for the crippled database, we must determine the semaphore set using the process of elimination. We issues the above commands for each live database on the server, and the un-claimed semaphore set will belong to the crippled instance.
Once identified, you can use the following procedure for removing the semaphore set.
We start by issuing the ipcs sb command to display details of the semaphore set.
root> ipcs
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x7403d635 1769472 root 600 4 0
0x00000001 1933313 root 600 655360 2
0x7403d60a 2523138 root 600 4 0
0x00000000 2883587 root 644 52 2
0x7403d609 2490372 root 600 4 0
0x00000000 2916357 root 644 16384 2
0x00000000 2949126 root 644 268 2
0x00000000 3014663 gdm 600 393216 2 dest
0xd3ac6c80 3080200 oracle 660 4096 0
------ Semaphore Arrays --------
key semid owner perms nsems
0x000000a7 0 root 600 1
0x5c23a1bc 131073 oracle 660 154
Now, we can remove the semaphores from the locked-up database. In this example, we assume that set 131073is the one for the crippled database.
root> ipcrm -s 131073
Now we can confirm that the semaphores are deleted.
root> ipcs -sb|grep oracle
s 67 0x00000000 --ra-r----- oracle dba 400
s 334 0x00000000 --ra-r----- oracle dba 300