TMPFS file system under Linux (/DEV/SHM)

Introduced

/ dev/shm/ is a device that uses the Tmpfs file system, which is actually a special file system. the default size in Redhat is half of physical memory, so that time is not mkfs formatted.

TMPFS is a memory-based virtual file system on the Linux/unix system . TMPFS can use your memory or swap partition to store the file ( that is, its storage space in virtual memory , the VM consists of real memory and swap ). Thus, TMPFS primarily stores staged files. It has the following 2 advantages: 1. The size of the dynamic file system. 2. Tmpfs uses a VM-built file system, which is of course fast . 3. data loss after reboot.

When you deletetmpfs  files  ,tmpfs vm  resources  ,  linux tmpfs tmpfs squid  /tmp, php session   files are placed in  /tmp, Socket  file in  /tmp,   or use  < Span lang= "en-US" >/tmp  as cache device for other apps

Temporarily modify the/DEV/SHM size

#mount-o size=1500m-o nr_inodes=1000000-o noatime,nodiratime-o remount/dev/shm

Mount-t tmpfs-o size=20m tmpfs/tmp temporary mount use

Boot-enabled configuration

You can define its size in/etc/fstab

Tmpfs/dev/shm tmpfs,defaults,size=512m 0 0

TMPFS/ tmp tmpfs defaults,size=25m 0 0

After the modification, the execution of mount-o remoount/dev/shm takes effect

Mkdir/dev/shm/tmp (the new directory under/dev/shm/is bound to/tmp , then/ tmp uses the tmpfs file System )

chmod 1777/dev/shm/tmp

Mount--bind/dev/shm/tmp/tmp

• Related articles recommended:
• Modify the/dev/shm Tmpfs file system size under Linux
• An explanation of the SSH configuration file
• Linux File system path learning
• This article from: Hobby Linux Technology Network
• This article link: http://www.ahlinux.com/start/base/9596.html

TMPFS file system under Linux (/DEV/SHM)