Platform & DevOps·Packaging: containers and images
the uploaded files were there all afternoon and gone after a restart, because they were written inside the container.
Ephemeral container filesystem
Also calledephemeral storage, writable layer
The rule that everything a container writes outside a mounted volume is discarded when it stops. It is deliberate — it is what makes a container replaceable — and it is the single most common surprise for an application ported from a virtual machine. It also has a capacity dimension: unbounded local writes fill the node's disk and get the workload evicted, taking well-behaved neighbours with it.