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This article shows you what the system parameters of Redhat in Linux are, which is concise and easy to understand, which can definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

Fs.aio-max-nr: the number of asynchronous IO requests that can be owned at the same time

Recommended value: 1048576, in fact, it is equal to 1024K.

Fs.aio-max-nr = 1048576

Fs.file-max: the number of files in the system that can be opened simultaneously.

Recommended value: fs.file-max = 512 * PROCESSES,6815744 is actually equal to 6.5m × 1024 × 1024mm.

Fs.file-max = 6815744

Kernel.shmmax: the maximum value used to define a single shared memory segment

Setting too low may result in the need to create multiple shared memory segments, which may lead to system performance degradation.

Recommended value: generally, the value should be greater than SGA_MAX_SIZE (you can also coordinate the use of PGA parameters and other memory such as OS, which cannot be set too full). You can take physical memory-1 bytejone 12GB physical memory, and take 30 "1024" 1024 "1024-1" 12884901887.

Kernel.shmmax = 4398046511104

Kernel.shmall: this parameter controls the total number of pages of shared memory that can be used.

Recommended value: shared memory segment size / shared memory page size

Shared memory segment size: kernel.shmmax

Shared memory page size: getconf PAGESIZE

Kernel.shmall = 1073741824

Kernel.shmmni: this parameter is the maximum number of shared memory segments.

Recommended value: the default value of shmmni is 4096, which is generally sufficient.

Kernel.shmmni = 4096

Kernel.sem:semmsl semmns semopm semmni

The value of semmsl, which represents the maximum number of semaphores that can be contained in a semaphore collection.

Recommended value: should be set to be greater than or equal to the largest PROCESSES parameter of all instances in the server + 10

The value of semmns that represents the maximum number of semaphores allowed in the system.

Recommended value: SEMMSL*SEMMNI should be set

The value of semopm that represents the number of operations that a single semopm () call can perform on a semaphore collection.

The value of semmni, which represents the total set of system semaphores.

Kernel.sem = 250 32000 100 128

Net.ipv4.ip_local_port_range: represents the range of IPv4 ports that the application can use.

Net.ipv4.ip_local_port_range = 9000 65500

Net.core.rmem_default: the default value that represents the size of the socket receive buffer.

Net.core.rmem_default = 16777216

Net.core.rmem_max: represents the maximum size of the socket receive buffer.

Net.core.rmem_max = 16777216

Net.core.wmem_default: the default value that represents the size of the socket send buffer.

Net.core.wmem_default = 16777216

Net.core.wmem_max: represents the maximum size of the socket send buffer.

Net.core.wmem_max = 16777216

The above is what are the system parameters of Redhat in Linux. Have you learned any knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

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