Docker D2 – Assignment2 – What is tempfs in docker volume and how it use it?
What is tmpfs ?
Assign memory from host’s RAM to the container which is normally outside of the write-able memory that the container gets when its created and run.
This memory will eventually get removed once container lifecyle ends
How to create tmpfs ?
Command to mount on /app in container with permission of 1770
docker run -itd --name test-tempfs --mount type=tmpfs,destination=/app,tmpfs-mode=1770 ubuntu
As we can see the filesystem for /app is created. Also notice this path /app doesn’t exist usually in a default ubuntu container
[root@ip-172-31-17-58 test-volume-bkp]# docker exec 7ed0760e1de5 df -kh Filesystem Size Used Avail Use% Mounted on overlay 100G 6.7G 94G 7% / tmpfs 64M 0 64M 0% /dev tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup shm 64M 0 64M 0% /dev/shm tmpfs 7.8G 0 7.8G 0% /app /dev/xvda1 100G 6.7G 94G 7% /etc/hosts tmpfs 7.8G 0 7.8G 0% /proc/acpi tmpfs 7.8G 0 7.8G 0% /proc/scsi tmpfs 7.8G 0 7.8G 0% /sys/firmware