Linux · btrfs

In btrfs terms, what is a subvolume, and how is it different from just making a directory?

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More in btrfs

When you modify a file on btrfs, what happens to the original disk blocks holding that data?

A colleague assumes btrfs is the universally adopted next-gen Linux filesystem. Where does the vendor picture actually diverge?

You suspect corruption on a btrfs filesystem and want to run a consistency check. What is the one hard precondition, and how do you actually make it repair errors?

You want to store a large database file or a VM disk image on btrfs without the usual COW fragmentation penalty. What do you set, and what is the catch on an existing non-empty file?

You mount a btrfs filesystem with compress=zstd and expect all existing files to shrink. Which files actually get compressed?

When you list subvolumes, the top-level root subvolume never appears in the output. What ID does it always carry, and why does that matter?

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