 So I did a video a few months ago about free NAS replication tasks. Free NAS replication, much like the name sounds will replicate data sets from one free NAS to another free NAS. This is an excellent way to use the power of ZFS to replicate data over to another ZFS system. Free NAS data makes this pretty easy to do with their interface. They have a really cool system for connecting it to another free NAS server. But I don't want people to mistake this for it's mirroring the server. It's mirroring the data sets you choose. Now I have, like I said, a more in-depth video that gets into how to set that up and showing how that works. But this mirroring process, in terms of mirroring a data set, not a server, works really, really well and is very efficient and can work over even a lower bandwidth connections. Because it uses the file level, the block level of ZFS to compare the two systems and get the data over to the other system. So any minor file changes you make, it can look at the binary differences between them, not just a file copy differences like other tools such as R-Sync, and then get that data moved over there. So it's looking at a differential between the data sets at the block level, which is one of the reasons it's so fast and efficient. Essentially it's referred to as like syncing the deltas. So the delta is the difference between one system and the other in terms of the files at the file level, block level. So this has been set up for quite a while. We've been using it for a long time and this is my LTS video work. So all the video files, because videos are big, we store them all on the free NAS. It makes it really easy to edit. My system has a 10 gig connection from the workstation I'm recording this on and it's dumping over a SMB share over to this free NAS box right here. It works really, really well. But of course, you know, I don't trust a single box because even though it's a RAID array, even though ZFS is very resilient, bad things happen sometimes and those bad things sometimes include entire server motherboard meltdown failure catastrophic. The other things that can happen are some weird corruption from some weird thing that happened as well. Like I said, there's all kinds of edge cases. You can't trust a single machine for backup ever. Just not a good idea. So we have the replication tasks and then we have the snapshots set up. Now these snapshots are also taken every day. So the replication is based on the snapshot frequency we snapshot daily, which means we replicate daily one day is fine for my videos. But for some scenarios for some clients when we put redundant servers in, they want snapshots done every hour because losing one hour of data has a cost associated with it. So maybe you want to set this more frequently. There is obviously a cost if I dumped a bunch of videos, I did them one day. Then the cash traffic failure happens before the replication task, but one day seems like a good enough risk for me for doing the data. Now keep snapshot for one week. I'm keeping snapshots for one week because that gives me seven days to figure out that I oops to file or deleted something. So for example, if I were to accidentally go in and purge something I needed, I have up to seven days from that snapshot was taken to roll back to it. And that's pretty easy to do. So we go to storage snapshots. And then you can choose a snapshot. Here's LTS video work from five nine, five four, you know, different dates here. And we could just clone or roll it back now rollback versus clone rollback means just reset it back to that state in that instance clone means create another copy of it so I can see something so I don't touch the main data. But I've made another folder essentially where I can look at what it looked like then and see the difference between them. These are, you know, features of snapshots. But what about the replication? Well, the replication goes over to another free NAS server. And we're still running the 11 one dash use seven train on this one because with this one we want it to because I have clients that still have questions about 11 one. This sometimes makes these rancher leaving a production but as those questions fall off I'll eventually swap this one 11 to but it works perfectly fine you can replicate between free NAS versions doesn't seem to be any compatibility problems that I found at all. But like I said eventually I will move this to 11 to now here's those same snapshots the replication test doesn't just replicate the last snapshot every replicates all the previous snapshots all the time so they also have one week retention. Now there's no snapshot task on here, doing this. So when you look at the periodic snapshot tasks. There's one for some other things we have on here but there's not one for there so with the replication test there's none on here because everything starts at the 3.8 and moves back over to this one. Well, I refer to this one as dozer and this one is tanks everything starts at dozer moves over to tank which is our 34 server. This data is being replicated between these. And way we go so we have a backup and the next part that people get a little bit confused about I'm going to show you what it looks like from a command prompt level is here is the dozer one at the bottom and here's all the video files and here's the tank one at the top and here's all the video files. I had just done this video for free NAS you for the other day and you can see it is there. Now this is where sometimes people get confused. Can you work off or edit from this other server. You'll mess things up if you do so there's not a way to do anything but read only all the files that are on the destination of the replication. So some people think that like there's an easy way just to push the data back. Free NAS doesn't have any automated one click push because the replication task takes a landing area that landing area being this particular free NAS server. And this is the source so this one pushes all the data over to this one but it's not a two way synchronization system this is not our sync this is not a mirroring system like a rate or a between two servers this is a it takes the data and moves over there. Now if you want to restore anything you have to go through either a create a replication task that sets the other server as a destination or our sync the files or copy the files via you know a share things like that. When it comes to restoring it's not like it's like oh there's a problem let me just hit a button and push it back the other way. Free NAS doesn't exactly work that way and this is a question it seems to come up quite a bit is can I just instantly mirror it back over there. That's not how this particular system works there are systems that do that for example I use syncing for some of our other data and by changing things in one syncing pool it will change it in the other syncing pools but that's a different tool and the same with our sync you can use our sync to our sync two folders that's another method you may want to use if you want that type of feature. So when you have it constantly are sinking between the two of them. When you do it in one it can push the changes back together and vice versa. So with this system here if there was a failure I would have to kind of manually do the data back this is not like fail over in NC but I want to make sure that's actually something I really want. So if anything does occur what I'm going to notice because while my video server be offline to I want to figure out what was the cause you know was it some type of destructive thing did someone get in there and hack something. Whatever the reason was over on this side I want to know before I start pushing the data I want to maintain this as a data integrity. Downside is with it automatically replicating if I you know had something in here that I deleted all the files and I waited seven days it would replicate away all that data so that's why you have to think about retention but I figure within seven days I'll notice something's wrong so I have seven days to catch up with fixing the problem. But it's actually pretty simple you can easily access all the data here I could just open up a share but once you do that do any type of read write on the replication it will stop replicating because it relies you tampered with the files and caused a lot of errors but not a big deal. The best way to do it would actually be because here's how it looks would be just to clone one of these snapshots for a read write and be able to pull the files out and create a share on it. The replicating data back is not that hard and that's what I wanted to cover there's not really a simple way to do it other than creating another replication task if you had to do it and let's walk through a catastrophic failure. If this server were to completely melt down destroy itself and be unrecoverable the drives through some type of why don't know lightning strike high powered surge that wrecks every drive simultaneously or it falls or something whatever something catastrophic or this drive is not recoverable. It wouldn't be that hard to simply build a new free NAS server. Go over here replication and replicate it back the other way that's actually completely possible once you've replicated it once that way you start the process over and replicate it back to this server if I needed to. So I just want to cover that kind of as a planning thinking about how you do these. Not that hard to do but there's not a one click backup for it's more or less what I would purpose this video because I've just every time someone asked well isn't there just a quick way to keep these in sync all the time and restore like a disaster recovery. There is but it's still kind of a manual process you just go through the replication process in reverse so it's not too hard to do it's just a simple process. But I kind of like it that way because you know you don't want it to if there's a problem on one to start pushing data back the other way you want to kind of do this in a controlled environment because ideally your data shouldn't be just disappearing so. We've been using it for a long time I've never had a problem with it I've actually never had to restore because I'm reasonably careful with the exception of that one time he deleted a music folder when I was purging out old videos. But that's the one time I had to do the restore and I just had to go through a snapshot excited oh oops and had to roll back one day to put my music folder back other than that I've never had a problem. Doing it but you know it's important to have all these things on here and it's if you didn't have them Murphy's Law says if you didn't have any backups you definitely would oops a bunch of things and not be able to roll back. So hopefully this is a helpful kind of explainer this still works great I will link to the snapshot video and how you do the replication down below. But it's so all the reasons we love CFS we love the way it works for in freeing asked to you know maintain and manage all the data that we have on here. It definitely works straight for that you can use this for other things such as if I wanted to snapshot and replicate for example all the VMs I have stored on here. I could but I actually still use Zen Orchestra to manage all the backups for that because I think it handles them in a better way. Alright thanks. Thanks again for watching this video and see you next time.