SQLITE_IOERR_SHMSIZEERRORTier 2 — Caution⚠️ MEDIUM confidenceI/O error resizing WAL shared-memory file
Category: I/O ErrorVersions: 3.7.0+
🔴 Production Risk Error
High — WAL writes will fail.
What this means
SQLITE_IOERR_SHMSIZE (4874) is returned when SQLite cannot extend the WAL shared-memory (-shm) file to the required size, usually because of a disk-full condition.
Why it happens
- 1Disk full preventing -shm file from being extended.
- 2OS error during ftruncate() or write() to the -shm file.
How to reproduce
WAL writes that require extending the -shm file.
trigger — this will ERROR
# df -h /path/to/database/ # check if disk is fullsqlite3.OperationalError: disk I/O error
Fix 1
Why this works
Free disk space on the filesystem containing the database.
Fix 2
Why this works
Use PRAGMA wal_autocheckpoint to keep WAL and -shm files small.
Sources
📚 Official docs: https://www.sqlite.org/rescode.html#ioerr_shmsize
🔧 Source ref: sqlite3.h — SQLITE_IOERR_SHMSIZE = 4874
Confidence assessment
⚠️ MEDIUM confidence
Stable.
See also
🔗 Related errors
📄 Reference pages
WAL mode
⚙️ This error reference was generated with AI assistance and reviewed for accuracy. Examples are provided to illustrate common scenarios and may not cover every case. Always test fixes in a development environment before applying to production. Spotted an error? Suggest a correction →