Btrfs Allocator Hints
10 months ago
- #Filesystem
- #Btrfs
- #Performance
- Introduces a new performance-based chunk allocation method for Btrfs using device roles.
- Defines 5 device roles: metadata_only, metadata, none, data, data_only, with specific allocation orders for metadata and data.
- Proposes Role-then-Space allocation method where metadata and data allocations prioritize devices based on their roles and free space.
- Discusses challenges in automatically determining device speeds and suggests external tools for setting device roles.
- Utilizes the unused on-disk field btrfs_dev_item::type to store device roles.
- Includes patches for refactoring and introducing new functionalities in Btrfs related to device roles and chunk allocation.