In this episode of The Linux Podcast with Fexingo, Lucas and Luna dive into the overlay filesystem — the unsung hero behind Docker and container image layers. They break down how overlayfs merges multiple directories into a single view, enabling efficient copy-on-write, small image sizes, and instant container startup. Lucas explains the mechanics of lowerdir, upperdir, and mergerdir, using a concrete example of a 500 MB base image with a 50 MB application layer. Luna asks how this differs from union mounts like aufs, and they discuss why overlayfs won out in the Linux kernel. The conversation also touches on performance trade-offs, use cases beyond containers, and why understanding overlayfs helps sysadmins debug storage issues. If today's tech conversation gave you something usable, consider supporting the ad-free mission at buy me a coffee dot com slash fexingo.

#Linux #OverlayFilesystem #OverlayFS #Containers #Docker #ContainerImages #CopyOnWrite #UnionMounts #AUFS #Kernel #Sysadmin #DevOps #Storage #Podman #ContainerLayers #Technology #FexingoBusiness #BusinessPodcast

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