SQLITE_IOERR_FSYNCFATALTier 3 — Handle with care⚠️ MEDIUM confidenceI/O error during fsync()
🔴 Production Risk Error
Critical — committed data may not be durable.
What this means
SQLITE_IOERR_FSYNC (1034) is returned when the OS reports an error during an fsync() or FlushFileBuffers() call. SQLite calls fsync() to ensure data is durably written to disk before completing a transaction commit.
Why it happens
- 1Disk hardware failure during fsync.
- 2Some filesystems (e.g., certain NFS mounts) return EIO on fsync.
- 3SSD firmware bug causing fsync failure.
How to reproduce
Transaction commit (COMMIT statement) when fsync() fails.
# Triggered by hardware or filesystem issues during COMMIT
# PRAGMA synchronous = FULL forces fsync on every commitFix 1
Why this works
Check filesystem and disk health: dmesg | grep -i fsync
Fix 2
Why this works
Use PRAGMA synchronous = NORMAL as a less aggressive alternative to FULL.
Fix 3
Why this works
Move the database to a local filesystem rather than NFS.
What not to do
Why it's wrong:
Sources
📚 Official docs: https://www.sqlite.org/rescode.html#ioerr_fsync
🔧 Source ref: sqlite3.h — SQLITE_IOERR_FSYNC = 1034
📖 Further reading: SQLite synchronous pragma
Confidence assessment
⚠️ MEDIUM confidence
Stable.
See also
📄 Reference pages