You probably know that reading from ram is a lot of faster than reading files from the hard drive, and reduces your disk io. When a tmpfs is full, it is full, just like any other file system. There is nothing abnormal about having tmpfs filesystems in your linux box. If you unmount a tmpfs instance, 6 everything stored therein is lost. A tmpfs has a specified maximum size, which defaults to half of physical memory. Then, well take a look at another capability introduced with linux kernel 2. Tmpfs virtual memory file system support former shm fs. Theres a standard memory device on each linux system except for some virtual machines depends on the virtualization technology devshm. Tmpfs is probably the best ram disklike system available for linux right now, and is a new feature of kernel 2. Users need to activate the following kernel options. Linux tmpfs previously known as shmfs is based on the ramfs code used during bootup and also uses the page cache, but unlike ramfs it supports swapping out lessused pages to swap space, as well as filesystem size and inode limits to prevent out of memory situations defaulting. Linux reimplementation of tmpfs is somewhat more flexible then solaris. Check the current volume information using df command like below. Other demands on physical memory may cause part of a tmpfs to be paged out to swap space, but the tmpfs can.
After extracting, the kernel checks to see if rootfs contains a file init, and if so it executes it as pid 1. So if you unmount a tmpfs file system, all the files residing in it are lost for ever. In this article i will show you how to resize tmpfs on linux machine. As the name implies, the content lives in ram, so it goes away after a reboot. In gnulinux ramfs random access memory file system has been replaced by tmpfs as. Tmpfs is probably the best ram disklike system available for linux right now, and was introduced with linux kernel 2. This is because you need to have kernel tmpfs support in order to use. Target source fstype options tmp tmpfs tmpfs rw,nosuid,nodev.