Here is how drush sql-sync works between two remotes:
- Logs into remote
@destination via SSH and creates destination database if needed via
- Backs up database on
sql-dump on source unless told otherwise and saves it into
@destination remote via SSH and executes
rsync to transfer database from Source to Destination.
rsync @source:drush-backups/db.sql.gz @destination:/tmp/db.sql.gz
To make this work, you have to make sure that:
- both local and remote drush have the same version (either 6.x or 7.x),
- on Destination the
@source alias should be accessible for drush,
rsync tool doesn't support two remotes, so only one may be remote.
Based on above it seems you can't use
sql-sync drush command to transfer the database between two remotes in drush 7.x (see: #161).
As for workaround, first dump the database from your source onto your local and transfer back to the destination, in example:
drush @source sql-dump | drush @destination sql-cli
This should transfer the database between two remotes without