What is the reason why Docker mounts Windows directory to MySQL data directory causing slow data import?

Docker mounts Windows directory to MySQL database resulting in slow data import parsing

This article analyzes the reason why MySQL database data is slow to import in Docker containers. This problem stems from mounting the Windows host directory to the MySQL 8.0 database data directory running in the Docker container (Linux environment), resulting in extremely slow import speed.

Users use Docker Compose to mount the ./mysqlData directory on the Windows host to /var/lib/mysql in the container, and the ./tmp directory to /tmp in the container. The import process is to first copy 21MB of SQL files to the ./tmp directory on the Windows host, and then import it using the mysql command in the container. However, this process took nearly an hour.

The core of the problem lies in the performance bottlenecks caused by the differences between Windows and Linux file systems. Docker mounts Windows directories into Linux containers, which will cause huge performance losses. This is not a problem with SQL file size, but the extremely low I/O speed of Linux containers accessing Windows file systems. This is because the underlying implementations of the two file systems are hugely different, and in the Docker virtualization environment, this difference is amplified, resulting in a significant drop in file access speed.

Therefore, the main reason for slow data import is that the container's I/O speed of reading and writing to mounted Windows directories ( ./tmp ) is too slow. For verification, it is recommended to conduct a comparison test: first copy the SQL file to the Linux virtual machine or the internal directory of the container, and then import it, and compare the import speed difference to confirm whether it is a problem caused by slow access to the Windows file system.

The above is the detailed content of What is the reason why Docker mounts Windows directory to MySQL data directory causing slow data import?. For more information, please follow other related articles on the PHP Chinese website!