IPCS command usage in Linux system

Use

Reports the status of interprocess communication facilities.

Grammar

The code is as follows:

IPCS [-mqs] [-abcopt] [-C core] [-N NameList]

-m outputs information about shared memory (shared memory)

-Q Output Information about the information queue (message queue)

-S output semaphore (semaphore) information

# ipcs-m

IPC status from as of April 10, 2007 Tuesday 18:32 18 sec CST

T ID KEY MODE OWNER GROUP

Shared Memory:

M 0 0x50000d43--rw-r--r--root root

M 501 0x1e90c97c--rw-r-----Oracle DBA

IPCRM-Remove IPC (Erase shared memory information)

Reference

It's syntax:

The code is as follows:

Ipcrm-m|-q|-s shm_id

-m outputs information about shared memory (shared memory)

-Q Output Information about the information queue (message queue)

-S output semaphore (semaphore) information

SHM_ID Shared Memory ID

#ipcrm-M 501

Describe

The IPCS command writes some information about the communication facilities between the active processes to the standard output. If no flags are specified, the IPCS command writes in a short format about the currently active message queues, shared memory segments, semaphores, remote queues, and local queue headers.

The column headings and the meanings of the columns in the IPCS command are listed below. The letters in parentheses denote the flags that cause the corresponding headers to appear. The all designer indicates that the header is always displayed. These flags only determine what information is provided to each device. However, they are not sure which devices will be listed.

IPCS View Message Queuing commands

The code is as follows:

Isd_1_3_sles10_64:/usr/local/services/httpd/bin # IPCS-QL

------Messages:limits--------

Max queues System Wide =16

Max size of message (bytes) = 65536

Default max size of queue (bytes) = 65536

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

To modify message Queue size:

The code is as follows:

Root: User:/etc/sysctl.conf

< P>KERNEL.MSGMNB =4203520

#kernel. MSGMNB =3520

Kernel.msgmni = 2878

After saving, you need to perform sysctl-p, and then rebuild all message queues

IPCS-Q: Show all message queues

IPCS-QT: Displays the time the message queue was created, when the last message was sent and received

The code is as follows:

goosns@[192.168.99.90:/hai]$ IPCS-QT

------message Queues Send/recv/change times--------

Msqid owner Send recv change

65536 Mas not set not set May 15 15:56:39

98305 Mas 15:59:22 may 15:59:22 15 15:56:39

IPCS-QP: Displays the process ID for placing messages in message queues and fetching messages from message queues

The code is as follows:

goosns@[192.168.99.90:/hai]$ IPCS-QP

------Message Queues PIDs--------

Msqid owner Lspid Lrpid

65536 Mas 0 0

98305 Mas 21941 21941

Ipcs-q-I msgid: Displays message information in this Message Queuing structure:

The code is as follows:

goosns@[192.168.99.90:/hai]$ Ipcs-q-I 98305

Message Queue msqid=98305

uid=512 gid=500 cuid=512 cgid=500 mode=0600

Cbytes=0 qbytes=4203520 qnum=0 lspid=21941 lrpid=21941

Send_time=thu May 15 16:00:19 2008

Rcv_time=thu May 15 16:00:19 2008

Change_time=thu May 15 15:56:39 2008

IPCS-QL: Displays the message queue's restriction information:

The code is as follows:

goosns@[192.168.99.90:/hai]$ IPCS-QL

------Messages:limits--------

Max queues System wide = 2878//maximum number of processes

Max size of message (bytes) = 8192//maximum length of messages in queue

Default max size of queue (bytes) = 4203520