I am trying to import a database into a slave server. The process is being slowed because mysql calls fsync at a crazy rate. The jbd2/dm-0-8 runs at 80 - 99 % continuously but the throughput is quite low. It was running at a few kb/s till I implemented the following changes
innodb_flush_sync = OFF
sync_binlog= 0
sync_frm = ON
sync_master_info = 0
sync_relay_log = 10000
sync_relay_log_info = 0
innodb_flush_log_at_trx_commit = 0
It's now running at about 12Mb/s. I'm sure if I can do something further to decrease fsync calls it will help this.
Any suggestions?
innodb_doublewrite = 0
andinnodb_flush_log_at_trx_commit = 0
depending on your MySQL version, too, but I wonder if the folks at [dba.se] might have more knowledge than us... – derobert Feb 07 '17 at 21:10