Blog/Btrfs-progs v5.15 released
2021-11-07: Btrfs-progs v5.15 was released with several new defaults!
The tree main things are in mkfs.btrfs:
- no-holes is enabled by default
- free-space-tree instead of space cache as default.
- DUP is now always used for metadata on single devices.
No-holes is an improved representation of file extents where holes are not explicitly stored as an extent. This saves a few percent of metadata if sparse files are used.
free-space-tree is an improved Space Cache that has much better performance, especially on larger filesystems. An explanation and a guide on how to switch to the new Free Space Tree is over at Btrfs/Space_Cache.
DUP profile for metadata improves the reliability of the filesystem. The earlier defaults had SINGLE profile as default for metadata on non-rotational drives such as NVME and SSD. However, if there were some minor corruption in the metadata, it could lead to a damaged filesystem. With DUP metadata, Btrfs can self-heal from many corruptions in the metadata, keeping your filesystem in a healthy state.