I've got big database (about 900GB), and when I migrate it to new server dump speed is not more than 2MB/s (very slow). Link between servers is 10Gb/s.
The database contain 20 tables with different sizes (the bigest one has about 600GB). Because servers have different version of postgresql (source 9.3 and destination 9.4) I can't copy all cluster to new server. I try using:
pg_dump -h source | pg_restore -h 127.0.0.1
but no result. I also try dump to file and then restore with '-j' parameter but also no result (after 20 min only one thread work because others finish their job). Problem isn't disk speed because both methods give me similar speed.
I haven't any experience with migrate such big data so maybe this methods are bad. Have You any advices why this migration is to slow, and how speed it up?