undefined_file could not open file “…”: No such file or directory — 58P01

Symptoms

PostgreSQL tried to open a file it expected to exist (a relation segment, WAL file, or other server file) but the OS reported it missing. This raises SQLSTATE 58P01 (undefined_file).

• A file the catalog references is absent on disk.
• Can indicate corruption, manual file deletion, or restore problems.
• The named path tells you what was expected.

What the server log shows

ERROR:  could not open file "base/16384/24576": No such file or directory

Why PostgreSQL raises this — what the manual says

Section 66.1 Database File Layout:

“Each table and index is stored in a separate file.”

System catalogs map relations to files on disk. When PostgreSQL needs a file that the catalog references but the OS cannot find it, it cannot read the data and reports 58P01.

Common causes

• Files manually deleted/moved from the data directory.
• An incomplete or inconsistent restore/copy.
• Filesystem corruption or a missing tablespace mount.

How to fix it

1. Ensure all tablespace mounts/paths are present and mounted.
2. Never manually modify the data directory; restore from a consistent backup.
3. Verify the restore copied every file; re-run from a known-good backup if not.

Related & next steps

• SQLSTATE 58P01 — Undefined File (full reference)
• Message: invalid page in block of relation
• Glossary: Tablespace

Reference: PostgreSQL 18 Section 76.1 “Database File Layout”.