如何快速转储 Postgres 数据库

Question

I have a massive Postgres 9.1 database (~450 GB) that I need to copy to a new machine, where I want to upgrade to Postgres 12.

Using pg_dump stalls out after a few hours, writing only 60 GB. How can I speed up the process dramatically?

Answer 1

Nothing is going to do what pg_dump does faster than pg_dump itself. Shut down access to the database while dumping if at all possible. Check the system for other sources of load (particularly I/O load) and remove them if possible. Check if the drive is failing. Don't write the dump to the same disk that the database is being read from (if another disk isn't available on the source machine, consider something like pg_dump whatever | ssh anothermachine 'cat > db.sql' ). Or, just have patience.

Answer 2

If you are dumping the database over ssh, add the -Z flag, followed by the zip level, to compress the output of pg_dump . eg, pg_dump -Z 9

See the documentation: https://www.postgresql.org/docs/9.3/app-pgdump.html