FreeNAS as backup storage. What is best practice for replicating large files?

[Dean Edwards]

I've been unable to find anything in this forum on this topic, but I'm new and may have missed something.

We have two sites, each with a single server hosting multiple Hyper-V virtual servers.

The local backup of each server generates a single file of about 1.2TB (though it slowly grows over time). The amount of data that changes on a daily basis is only about 25-30GB.

We want to setup a FreeNAS system at each site to store the backups, and then replicate the backups between each other so that the backup at site A is replicated to NAS on site B and visa versa.

Is it better to use Rsync, ZFS replication, or some other process to accomplish this? Or is FreeNAS even the best solution for this scenario?

If the recommendation is to use ZFS replication, could anyone summarize how that is setup for a newcomer like myself? Is it, for example, possible to seed the remote FreeNAS device with a copy of the local FreeNAS backup file so the initial sync doesn't take infinity over a relatively slow WAN connection of 1-2Mbps?

 

[Robert Trevellyan]

The step by step directions are in the user guide.

Is it, for example, possible to seed the remote FreeNAS device with a copy of the local FreeNAS backup file

To accomplish this, you would do the initial replication on your LAN.

 

[nightshade00013]

The bad thing is with a connection speed of that nature even 25 to 30 GB of change would take 31 to 37 hours to transfer. With a connection of that speed your best option is to do the old fashioned once a week ship a drive back and forth for the transfer. You would need to have a minimum upload speed on each end of around 5 to 10 Mbps to get into the 12 to 6 hour range and that is dedicating the connection to transfer during that timeframe and only transferring changes.

 

[Dean Edwards]

The bad thing is with a connection speed of that nature even 25 to 30 GB of change would take 31 to 37 hours to transfer. With a connection of that speed your best option is to do the old fashioned once a week ship a drive back and forth for the transfer. You would need to have a minimum upload speed on each end of around 5 to 10 Mbps to get into the 12 to 6 hour range and that is dedicating the connection to transfer during that timeframe and only transferring changes.

Actually, we are planning to upgrade our internet connection. We should end up with about 20-25 Mbps connection within a couple of months, and there is virtually zero traffic at night other than the planned replication.

So the question remains...is it better to use Rsync, ZFS replication, or go another direction like Windows Storage Services w/DFS?

 

[nightshade00013]

Will that be a symmetrical or asymmetrical connection? It does matter since on a 20 to 25 Mbps connection that is asymmetrical you will be in the 3 to 4 Mbps range for upload, it MAY squeak by at that level but anything extra and there will be some problems.

rsync should work to backup the incremental changes of the file from my understanding but I have never put it into practice. Most of my stuff is done with Syncthing with files ranging up to 4GB and only adding or removing them. You will still need to either have both boxes on the lan or send a drive with the latest version so it can be copied over before rsync is put into use.

 

[Robert Trevellyan]

We want to setup a FreeNAS system at each site to store the backups

In general, with a FreeNAS at each location, ZFS replication is the way to go.

 

[Rand]

I'd second the ZFS replication for your use case, you will have to run two jobs though (one sending to B, one sending to A) just to be clear on that as only rsync is two way.