" The B-tree file system Btrfs is a next-generation filesystem
for Linux, and although it is still undergoing rapid development,
you can use it for day-to-day tasks. Even if you are not prepared
to migrate your production servers over to Btrfs, you should take
some time to explore what it can do. It offers significant time-
and space-efficiency improvements over ext3/ext4 — not to
mention considerably simpler volume management.
"For those unfamiliar, Btrfs is a clean break from the approach
used in Linux's ext filesystems in years past. It uses b-trees to
store generic "items" of varying data types in a single, unified
data structure. Items are sorted by their 136-bit key, which groups
related items together via a shared key prefix (and thus
automatically optimizes the filesystem for large read and write
operations). Small files can be stored directly in the tree leaves,
while large files are written in extents —which lowers the
overhead and reduces fragmentation."