Info: File system images

Antti Kantee edited this page Feb 27, 2016 · 5 revisions
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Though a rump kernel does not require a root file system image, some applications and library routines expect to be able to access files. For example, the getservent() call searches /etc/services, and a web server serving static content typically serves it from a file system hierarchy. To satisfy these demands, we mount file systems in the rump kernel file system namespace. Any file system type, e.g. NFS, would do, but it's usually simplest mount a prepopulated image.

Rumprun includes a tool calls cookfs which, when given a directory tree, produces an object file which can be baked into the unikernel. Cookfs is available as tuple-cookfs, e.g. x86_64-rumprun-netbsd-cookfs. Rumprun-bake uses cookfs to include an automatically available skeleton /etc sufficient for most purposes.