Shulou(Shulou.com)06/01 Report--

Explain the environment, is the current network real-time production database host. Hp-ux 11.31+Oracle 10.2.0.4.0 RAC cluster.

Two machines, outdoor RAC,essdb3 and essdb4 machines.

128G of physical memory for SGA allocation 64G for PGA allocation of 5G for PGA. In the morning, it was found that the essdb4 host glance was running only 6G of free memory.

Use the following command for a simple analysis:

SQL > select distinct sid from vault mystat; get the sid and calculate how much pga an idle process takes up.

SQL > select b.PGA_USED_MEM PGA_USED_MEM, b.PGA_ALLOC_MEM PGA_ALLOC_MEM,b.PGA_FREEABLE_MEM PGA_FREEABLE_MEM,b.PGA_MAX_MEM PGA_MAX_MEM from v$session a, v$process b where a.PADDR=b.ADDR and a.sid ='& sid'

Enter the SID number you just got. Calculate the approximate memory consumed by an idle process, and the total PGA usage of the system is basically stable between 1.29g and 2G (the maximum PGA set by the system is 5G), which is also a very reasonable state compared with usual.

SQL > select sum (PGA_USED_MEM) from v$process

SUM (PGA_USED_MEM)

-

1298679359

We use ipcs to observe the usage of shared memory segments:

Essdb4_ Oracle [/ var/adm/syslog] $ipcs-mb

IPC status from / dev/kmem as of Thu Jun 23 10:18:00 2016

T ID KEY MODE OWNER GROUP SEGSZ

Shared Memory:

M 0 0x411c06cb-rw-rw-rw- root root 348

M 1 0x4e0c0002-- rw-rw-rw- root root 61760

M 2 0x4120077b-rw-rw-rw- root root 8192

M 3 0x00a5c581-rw- sfmdb users 10469376

M 4 0x411c14fb-rw- root root 4096

M 13893637 0x00000000-rw-r- oracle oinstall 18790481920

M 6 0x06347849-rw-rw-rw- root root 65544

M 7 0x0c6629c9-- rw-r- root root 22614264

M 32776 0x01205c0a-rw-rw-r-- root root 4192

M 9 0x00000000 Dmurf RW Murray-root root 4192

M 10 0x00000000 Dmurf RW Murray-root root 4192

M 11 0x4918a061-rw-r--r-- root root 22912

M 12 0x0120468b-rw-rw-r-- root root 4192

M 13 0x00000000-- rw-r- oracle oinstall 18807521280

M 14 0x00000000-rw-r- oracle oinstall 18807259136

M 15 0x00000000-- rw-r- oracle oinstall 12367142912

M 16 0x3546761c-rw-r- oracle oinstall 135168

Detailed usage information of shared memory:

Essdb4_oracle [/] # ipcs-mb

IPC status from / dev/kmem as of Thu Jun 23 13:42:57 2016

T ID KEY MODE OWNER GROUP SEGSZ

Shared Memory:

M 0 0x411c06cb-rw-rw-rw- root root 348

M 1 0x4e0c0002-- rw-rw-rw- root root 61760

M 2 0x4120077b-rw-rw-rw- root root 8192

M 3 0x00a5c581-rw- sfmdb users 10469376

M 4 0x411c14fb-rw- root root 4096

M 13893637 0x00000000 Dmurf rwmurr-oracle oinstall 18790481920

M 6 0x06347849-rw-rw-rw- root root 65544

M 7 0x0c6629c9-- rw-r- root root 22614264

M 32776 0x01205c0a-rw-rw-r-- root root 4192

M 9 0x00000000 Dmurf RW Murray-root root 4192

M 10 0x00000000 Dmurf RW Murray-root root 4192

M 11 0x4918a061-rw-r--r-- root root 22912

M 12 0x0120468b-rw-rw-r-- root root 4192

M 13 0x00000000-- rw-r- oracle oinstall 18807521280

M 14 0x00000000-rw-r- oracle oinstall 18807259136

M 15 0x00000000-- rw-r- oracle oinstall 12367142912

M 16 0x3546761c-rw-r- oracle oinstall 135168

The state of the shared memory segment is D-Delete, which is not normal under normal circumstances. This is a shared memory segment occupied by Oracle users. Because the shared memory segment with status D itself is not in normal use, I fully think that deleting this shared memory segment with ipcrm-m id should solve the problem. However, the result of the above practice at that time was that the system reported that it could not find an ID.

Essdb4_oracle [/] # ipcrm-m 13893637

Now let's use shminfo to use root permission to see which process is currently using to find a shared memory segment:

Essdb4_oracle [/] # shminfo-s 13893637

Sh: shminfo: not found.

Finally, the reboot of the node database still holds the shared memory, and in the end, the operating system can only be rebooted and freed. The current system has 40 GB of available memory.

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