OSD developer documentation

Contents

• Asynchronous Recovery
• Backfill Reservation
• Erasure Coded Placement Groups
  • Glossary
  • Table of content
    • Developer notes
      • Introduction
      • Reading and writing encoded chunks from and to OSDs
      • Erasure code library
      • Notes
    • Jerasure plugin
      • Introduction
    • ECBackend Implementation Strategy
      • Misc initial design notes
        • PGTemp and Crush
        • Distinguished acting set positions
        • Object Classes
        • Scrub
        • Crush
    • ECBackend
      • MAIN OPERATION OVERVIEW
        • WHOLE STRIPE WRITE
        • READ-MODIFY-WRITE
        • OSD Object Write and Consistency
        • ExtentCache
        • Pipeline
• last_epoch_started
• Log Based PG
  • Background
    • Why PrimaryLogPG?
    • Primary log-based replication
  • ReplicatedBackend/ECBackend unification strategy
    • PGBackend
  • PGBackend Interface Explanation
    • Readable vs Degraded
    • Client Reads
    • Scrub
    • Recovery
• Map and PG Message handling
  • Overview
  • MOSDMap
  • MOSDPGOp/MOSDPGSubOp
  • CEPH_MSG_OSD_OP processing
  • Peering Messages
• OSD
  • Concepts
  • Overview
• OSD Throttles
  • WBThrottle
  • op_queue_throttle
  • journal usage throttle
• Partial Object Recovery
  • Procedures for Partial Object Recovery
• PG
  • Concepts
  • Peering Details and Gotchas
• PG Removal
• PGPool
• Recovery Reservation
  • Dump Reservations
  • Things to Note
  • See Also
• Scrub internals and diagnostics
  • Scrubbing Behavior Table
  • State variables
  • Scrub Reservations
• Snaps
  • Overview
  • Ondisk Structures
  • Snap Removal
  • Recovery
  • SnapMapper
  • Split
• Preventing Stale Reads
  • readable_until
  • Prior Intervals
  • PG “laggy” state
  • PG “wait” state
  • Dead OSDs
• Watch Notify
  • Overview
  • Watch Lifecycle
  • Notify Lifecycle
• Writeback Throttle