Linux ipcs command

Linux ipcs command ipcs: mainly provides the calling process to read and access some ipc device information. for example, shared memory, semaphores, and Message Queue ipcs [-asmq] [-tclup] ipcs [-smq]-I id-m output shared memory (shared memory segments) information-s output semaphores (semaphore) information-q Output message Queue (message queues) information-l limits 01root@10.1.1.45: log # ipcs02 03 ------ Shared Memory Segments -------- 04key shmid owner perms bytes nattch status 05 06 ------ Semaphore Arrays -------- 07key semid owner perms nsems 080x%2af9 131 072 db 664 1 090x00002afb 163841 db 664 1 100x00002b03 65538 db 664 1 110x00002b05 98307 db 664 1 12 13 ------ Message Queues -------- 14key msqid owner perms used-bytes messages where Key is the application to access resources parameters used, id is the unique id of the resource entry. for example, the database user program may be started with the root account. In this case, the root account first closes the database user program, but the shared memory may not be released and needs to be deleted manually. this requires the ipcrm command. ipcrm-remove a message queue, semaphore set or shared memory id ipcrm [-M key |-m id |-Q key |-q id | -S key |-s id]-m shmid-q msqid-s semid 01root@10.1.1.45: log # ipcs-s02 03 ------ Semaphore Arrays -------- 04key semid owner perms nsems 050x4252af9 131072 db 664 1 060x4152afb 163841 db 664 1 070x%2b03 65538 db 664 1 × 98307 db 664 10root@10.1.1.45: log # ipcrm-s 13107211root@10.1.1.45: log # ipcrm-s 16384112root@10.1.1.45: log # ipcrm-s 6553813root@10.1.1.45: log # ipcrm-s 983 0714 15root@10.1.1.45 :~ # Ipcs16 17 ------ Shared Memory Segments -------- 18key shmid owner perms bytes nattch status 19 20 ------ invalid Arrays -------- 21key semid owner perms nsems 22 23 ------ Message Queues -------- 24key alias owner perms used-bytes messages 01root@10.1.1.45: ~ # Ipcs-l02 03 ------ Shared Memory Limits -------- 04max number of segments = 409605max seg size (kbytes) = 3276806max total shared memory (kbytes) = 838860807 min seg size (bytes) = 108 09 ------ Semaphore Limits -------- 10max number of arrays = 12811max semaphores per array = 25012max semaphores system wide = 3200013max ops per semop call = 3214 semaphore max value = 3276715 16 ------ Messages -------- 17max queues system wide = 1618max size of message (bytes) = 819219 default max size of queue (bytes) = 16384 there are two ways to change its value 1. change/etc/sysctl. conf, add kernel. msgmni = 1024, effective load configuration using sysctl-p kernel. msgmni this file specifies the maximum number of Message Queue IDs, that is, the maximum number of message queues in the system range. 1root@10.1.1.45 :~ # Cat/proc/sys/kernel/msgmni2163root@10.1.1.45 :~ # Vim/etc/sysctl.conf4root@10.1.1.45 :~ # Sysctl-p5kernel. msgmni = 10246root@10.1.1.45 :~ # Cat/proc/sys/kernel/msgmni710242. use the sysctl command under root to take effect directly. 1root@10.1.1.45 :~ # Sysctl-w kernel. msgmni = 162kernel. msgmni = 163root@10.1.1.45 :~ # Cat/proc/sys/kernel/msgmni416