pre-seeding databases from remote servers for multi-source replication

I'm in the process of pre-seeding a mariadb 10.0.9 multi-source replica server with databases from remote 5.5 servers. I'm looking for the fastest and most stable way of doing this (preferably without using mysqldump).

I'm curious if there is a way to import entire databases directly from block-level snapshots, similar to the transportable tablespaces (only on a database level instead of a table level, by copying .idb/.frm/etc. files directly to the target server). NOTE: Transportable tablespaces aren't yet available in 5.5 and also have to be done on a table-by-table basis.

Some of the databases are large enough that running mysqldump & import will are impractical. Not only will this process take a considerable amount of time, but to do this in a way that is closest to a snapshot will require a separate server instance to ensure all transactions have been committed to the tablespaces.

Is there anyone out there looking at multi-source replication who has a simple solution to this that i might be overlooking?

Thank you.