Thank you Kevin. Yes, i read documentation about how snapshot works and though that replication task only copy refer data of each snapshot.
So i dont clearly understand now... I keep snapshot for 2 week with 1 hour interval. What info is copied in remote with this configuration?
Others have answered this question, but I'll illustrate with my setup and the outcome.
I've got several recursive snapshots set up at various intervals and retentions: hourly snapshots with 2 day retention, daily snapshots with a 30 day retention, and every four week snapshots with a 1 year retention.
The replication task to the backup server is set up to run from 1830 to 0630, so it occurs when the network that the backup server is on will be less busy. After the replication was set up, the first run took a long time, as a full copy of the data and all snapshots was copied over. Every day at 1830, when it starts back up again, it takes a few minutes, as all the snapshots from 0630 to 1830 are copied. The task runs again every hour, and copies the last hourly snapshots, which are usually very small, unless some large file has been added or modified.
If I look at the backup server, I see that it has the same long list of snapshots as the main server.
I tested what happens if communication between the two servers is lost for several days. In this case, the replication picks up where it left off, and sends over all the snapshots that were made in the period when communication was lost.
I've got also got a backup pool on my main server, and use replication to keep it matching the data on the main pool.