Tmpfs

tmpfs (temporary file system) (formerly known as shmfs) is Article description::a virtual [[filesystem created to store files in dynamic (volatile) memory.]] tmpfs is typically created on RAM.

In Linux ramfs (random access memory file system) has been replaced by tmpfs as the old ramfs did not handle well when the system run out of memory. tmpfs allows the filesystem to grow dynamically when it needs more space until it hits the pre-set maximum value it has been allocated; after that it will use swap space if it is available.

There are many cases for using temporary file systems in Linux, one being the directory which does not need to physically store non-volatile data.

Installation
Users need to activate the following kernel options:

Usage
Generate and mount tmpfs in one step:

Users can specify the mount option size to control the maximum size of the filesystem (default: half of your memory). Note that tmpfs doesn't reserve this memory, but allocates only the needed memory.

systemd
When using systemd the directory is mounted by default as tmpfs and given a default size which is deemed big enough without chewing up too much RAM.

Users can view mounted temporary filesystems using the following command:

This will show if the mount point is a tmpfs filesystem and the size of such filesystem.

In order to disable this behaviour and take back control of the directory by using the user needs to run the following command:

This command will now not mount as a tmpfs and will automatically switch back to a block device.

Users should now add a new line in which will create a tmpfs for  manually.

OpenRC
OpenRC users should simply add the mount point into :

Other directories to consider
Here are a few other directories users may mount as a tmpfs in order to boost their system performance. Use the command to check if they are already use tmpfs before attempting to manually mount them in.

Conclusion
The outcome of using a temporary filesystem for non volatile files such as the directory is that the system has a very fast and very responsive access to caching files and stored session media. This also helps when using a browser to surf the web as cookies can be stored on this volatile media speeding up the application; on every reboot they are scrubbed or wiped from RAM. If users need to keep temporary files for analytics then they should avoid using the tmpfs filesystem for and other directories. All data stored in the tmpfs mount point will be lost when the system is rebooted or powered down.

Advancements in technology
Some hardware manufactures provide devices that are slower than RAM but faster than SSD to be used as cache drives. These devices are usually incorporated on a PCIe add-in card and have either an adapter from PCIe to M.2 slot or the entire memory device is embedded into the PCIe card.

If users need a non-volatile high speed versatile solution faster than SSD/SAS/SATA then these high speed solutions should be considered. Of course users should not mount these devices with tmpfs but instead use a conventional partitioning filesystem.

Technology such as the Intel 3Dx Optane memory cache can be used too, but this technology, although more versatile than SSD, is still subject to wearing out. It does however provide a brilliant midway point that will only get better as the technology progresses in the future and provides us with a much faster computing experience when setup correctly.