如何查询oracle的共享内存,[20190104]ipcs查看共享内存段.txt

[20190104]ipcs查看共享内存段.txt

--//数据库启动异常,有时候会留下一些共享内存段没有清理,需要使用ipcrm清理.

--//由于服务器上跑2个实例,必须选择正确的共享内存段,否则会导致别的数据库crash.

--//在我工作中,这是遇到的第2次,做一些复习与整理:

--//在linux下有一个命令sysresv可以查看某实例使用的共享内存段.

$ ipcs

------ Shared Memory Segments --------

key shmid owner perms bytes nattch status

0x00000000 287440897 oracle 600 12288 2 dest

0x00000000 287473666 oracle 600 196608 2 dest

0x00000000 287506435 oracle 600 12288 2 dest

0x00000000 287211524 oracle 600 393216 2 dest

0x00000000 287244293 oracle 600 393216 2 dest

0x00000000 287277062 oracle 600 393216 2 dest

0x00000000 287309831 oracle 600 196608 2 dest

0x00000000 287342600 oracle 600 393216 2 dest

0x00000000 287375369 oracle 600 196608 2 dest

0x00000000 287408138 oracle 600 393216 2 dest

0x00000000 301334539 oracle 640 12582912 25

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

0x00000000 301367308 oracle 640 633339904 25

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

0xe8a8ec10 301400077 oracle 640 2097152 25

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

0x790209cd 294617102 oracle 666 808 0

0x79020002 294649871 oracle 666 808 0

------ Semaphore Arrays --------

key semid owner perms nsems

0x6aa88594 275578880 oracle 640 184

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

0x790209cd 269713409 oracle 666 1

0x79020002 269746178 oracle 666 1

------ Message Queues --------

key msqid owner perms used-bytes messages

$ export ORACLE_SID=book

$ sysresv

IPC Resources for ORACLE_SID "book" :

Shared Memory:

ID KEY

301334539 0x00000000

301367308 0x00000000

301400077 0xe8a8ec10

Semaphores:

ID KEY

275578880 0x6aa88594

Oracle Instance alive for sid "book"

--//下划线内容可以对上.

--//注意执行前最好指定确认ORACLE_SID环境变量.

man ipcrm

-m shmid removes the shared memory segment identified by shmid after the last detach is performed.

--//ipcrm 参数-m 对应 shmid.

--//另外ipcs有一个参数-t参看time.

$ ipcs -t

------ Shared Memory Attach/Detach/Change Times --------

shmid owner attached detached changed

287440897 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 17:32:14

287473666 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 17:32:14

287506435 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 17:32:14

287211524 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:08

287244293 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:08

287277062 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:08

287309831 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:08

287342600 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:09

287375369 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:17

287408138 oracle Dec 12 17:37:06 Dec 12 17:37:07 Dec 5 15:42:17

301334539 oracle Jan 4 10:13:32 Jan 4 10:14:02 Jan 4 09:53:20

301367308 oracle Jan 4 10:13:32 Jan 4 10:14:02 Jan 4 09:53:20

301400077 oracle Jan 4 10:13:32 Jan 4 10:14:02 Jan 4 09:53:20

294617102 oracle Dec 24 09:22:37 Dec 24 09:22:37 Dec 24 09:22:37

294649871 oracle Dec 24 10:03:22 Dec 24 10:08:55 Dec 24 09:23:01

------ Semaphore Operation/Change Times --------

semid owner last-op last-changed

275578880 oracle Fri Jan 4 10:14:43 2019 Fri Jan 4 10:14:43 2019

269713409 oracle Mon Dec 24 09:22:37 2018 Mon Dec 24 09:22:37 2018

269746178 oracle Mon Dec 24 10:08:55 2018 Mon Dec 24 09:23:01 2018

------ Message Queues Send/Recv/Change Times --------

msqid owner send recv change

--//我仔细看了一下.如果有用户连上attached会变化,退出后detached时间也会变化.说明有用户使用.

--//最后一列changed视乎都不变,不知道是否对应oracle实例的启动时间.

SYS@book> select startup_time from v$instance ;

STARTUP_TIME

-------------------

2019-01-04 09:53:21

--//视乎可以对上.

--//另外使用oradebug ipc命令也可以查看.

SYS@book> oradebug setmypid

Statement processed.

SYS@book> oradebug ipc

IPC information written to the trace file

SYS@book> oradebug tracefile_name

/u01/app/oracle/diag/rdbms/book/book/trace/book_ora_7252.trc

*** 2019-01-04 10:25:15.026

Processing Oradebug command 'ipc'

Dump of unix-generic skgm context

areaflags 000000f7

realmflags 0000001f

mapsize 00000800

protectsize 00001000

lcmsize 00001000

seglen 00200000

largestsize 0000000480000000

smallestsize 0000000000400000

stacklimit 0x7fffc0268300

stackdir -1

mode 640

magic acc01ade

Handle: 0x7f0b488e40b0 `/u01/app/oracle/product/11.2.0.4/dbhome_1book'

--//注意这是句柄,还记得环境变量ORACLE_HOME后面带斜线的设置导致无法连上数据库的问题吗?11.2.0.4已经没有这个问题了.

$ echo $ORACLE_HOME

/u01/app/oracle/product/11.2.0.4/dbhome_1

--//参看链接:http://blog.itpub.net/267265/viewspace-2055052/=>[20160310]神奇的斜线.txt

Dump of unix-generic realm handle `/u01/app/oracle/product/11.2.0.4/dbhome_1book', flags = 00000000

Area #0 `Fixed Size' containing Subareas 0-0

Total size 0000000000226c00 Minimum Subarea size 00000000