MySQL Error 2006: Server Has Gone Away (During Import)

Importing a SQL file and it fails partway through with 'ERROR 2006 (HY000): MySQL server has gone away'. Your import is dead, your database is half-populated.

What this error actually means

MySQL closed the connection. This usually happens because:

1. Packet too large — A single query exceeded max_allowed_packet
2. Connection timeout — The query took too long (wait_timeout)
3. Server crashed — Less common, but possible with huge queries

During imports, it's almost always #1 or #2.

Fix for max_allowed_packet

If you can change MySQL settings:

SET GLOBAL max_allowed_packet=512*1024*1024;

Or add to my.cnf and restart MySQL:

[mysqld]
max_allowed_packet=512M

Fix for wait_timeout

SET GLOBAL wait_timeout=28800;
SET GLOBAL interactive_timeout=28800;

This sets 8-hour timeouts. Overkill for most imports, but it won't hurt.

Can't change MySQL settings?

On shared hosting, you probably can't. Your options:

• Split the SQL file into smaller chunks
• Re-export with smaller INSERT statements (--skip-extended-insert)
• Ask your host to import it for you

Recovering from a partial import

If the import died halfway, your database is probably in a bad state. You have two options:

1. Drop all tables and start over — Safest. DROP DATABASE, CREATE DATABASE, try again.
2. Figure out where it stopped — Harder. You'd need to check which tables have data and resume from there.

For a clean import, starting over with properly split files is usually less painful than debugging a partial import.