1. btrfs: Introduction and Performance Evaluation Douglas Fuller Oak Ridge Leadership Computing Facility / ORNL LUG 2011

2. 2Managed by UT-Battelle for the U.S. Department of Energy btrfs: overview Implemented in Linux 2.6.29 64-bit Extent-based Copy on write Multiple devices – Object pools (RAID-0, RAID-1, and RAID-10 for now) – Dynamic rebalancing Subvolumes with snapshots Available transparent compression (zlib)

3. 3Managed by UT-Battelle for the U.S. Department of Energy btrfs: still to come Erasure coding (RAID-5/RAID-6) fsck Dedup Encryption

4. 4Managed by UT-Battelle for the U.S. Department of Energy Goals Determine baseline btrfs performance Evaluate pooling at the filesystem layer – Avoids expensive RAID controllers – Provides additional features Evaluate overhead from additional features

5. 5Managed by UT-Battelle for the U.S. Department of Energy Test Platform Target: LSI Engenio (xbb2), 1TB fibre channel disks – DDR InfiniBand – Each disk on a separate backend channel – Controller write cache disabled – O_DIRECT – 1MB request sizes – I/O elevator noop Initiator – Nehalem with Linux 2.6.37 – SRP

6. 6Managed by UT-Battelle for the U.S. Department of Energy Baseline Performance

7. 7Managed by UT-Battelle for the U.S. Department of Energy Sequential write

8. 8Managed by UT-Battelle for the U.S. Department of Energy Sequential read

9. 9Managed by UT-Battelle for the U.S. Department of Energy Random write

10. 10Managed by UT-Battelle for the U.S. Department of Energy Random Read

11. 11Managed by UT-Battelle for the U.S. Department of Energy Untar

12. 12Managed by UT-Battelle for the U.S. Department of Energy Untar with compression

13. 13Managed by UT-Battelle for the U.S. Department of Energy Random reads with compression

14. 14Managed by UT-Battelle for the U.S. Department of Energy Random write with compression