Loic Dachary, Red Hat

1. Erasure Code in Ceph
Loic Dachary @ Red Hat

2. Save Space

3. 5 minutes role playing game

4. XOR

5. 3 peta => 1.3 peta

6. Harder object mutations / recovery

7. Simple operations and tiering
Replicated Erasure Coded

8. Promoted to replica on read
Replicated Erasure Coded

9. Sam & David : internals

10. Janne & Andreas & Loic & Takeshi
erasure code

11. Released May 2014 : Firefly

12. Why save space before shortage ?

13. Reliability Model
● After an OSD is lost
● Recovery
● Backfilling a new OSD

14. April 2015 : Hammer

15. Repair K=10, M=4

16. Locally Recoverable Codes
LRC @ Red Hat

17. SHEC Takeshi @ Fujitsu

18. ISA plugin Yuan @ Intel
SIMD aka SSE2, SSE3, SSE4
Only for Intel processors
~50% Faster

19. jerasure ARM Janne @ ARM

20. Infernalis

21. Hitchhiker Rashmi @ U.C. Berkeley

22. ldachary@redhat.com
Artwork GPLv3+ Tartaruga Feliz