MySQL Error 1696: ER_FAILED_READ_FROM_PAR_FILE - How to Fix and Prevent

What is MySQL Error 1696 ER_FAILED_READ_FROM_PAR_FILE?

MySQL raises error code 1696 with the message Failed to read from the .par file when it cannot open or parse the partition description (.par) file associated with a partitioned table. The .par file stores critical partition metadata, so any read failure stops the server from opening the table.

The problem appears during table access, startup, ALTER TABLE, or backup operations. If the file is damaged or inaccessible, MySQL prevents further operations to protect data integrity.

What causes this error?

Most cases trace back to file system issues. Deleted, renamed, corrupted, or permission-restricted .par files break the metadata link. Inconsistent backups that omit .par files also trigger the error. Storage hardware faults or incomplete replication can corrupt the file header, producing the same failure.

Version mismatches during upgrades can leave outdated .par formats that the current server cannot parse, resulting in the read failure.

How do I fix MySQL Error 1696?

First, stop writes to the affected table to avoid further corruption. Verify that the .par file exists in the table directory and that the MySQL OS user has read permissions. Restore the file from a recent backup if it is missing or corrupted.

If no valid backup exists, recreate partition metadata by exporting data, dropping partitions, and re-adding them. MySQL automatically generates a new .par file during ALTER TABLE ... REBUILD PARTITION;.

Common scenarios and solutions

Backup-restore workflows often omit .par files. Always copy the full schema directory, then verify checksums before restart. On replication slaves, ensure the partitioned table was created with the same definition, or run ALTER TABLE ... REMOVE PARTITIONING; followed by the correct partition statement to regenerate metadata.

Filesystem permission changes after OS hardening can lock out the MySQL user. Reset ownership with chown mysql:mysql on Linux or adjust ACLs on Windows to restore access.

Best practices to avoid this error

Use logical backup tools like mysqldump or MySQL Shell dump that capture partition definitions instead of copying raw files manually. When performing physical backups, include both .frm and .par files and validate them using CHECK TABLE.

Monitor error logs for early warnings, and enable read-only health checks that run SELECT 1 FROM table LIMIT 1 on critical partitioned tables. Automate alerts in Galaxy so teams catch missing files before users notice outages.

How Galaxy helps you avoid this error

Galaxy surfaces MySQL server errors instantly in its editor, highlighting the failing query and linking directly to documentation. Versioned query storage and access control reduce the chance of ad-hoc file manipulations. Built-in run history lets engineers trace when the partition definition last changed, speeding recovery.