DFS Replication

[Trapper]

Hello All,

 

When using DFS to run the initial replication of data between servers is the only option to let Windows take care of this?

 

Could I not use ROBOCOPY to take the data up on portable storage with all NTFS permissions and SIDs intact?

 

Basically the data size is around 500GB and we have a 100Mbps (up and down) fibre link between sites, but even at that speed it'll take days.

[sted]

dfs replication is flakey at the best of times in my experience I wouldn't risk doing anything that it might not like

[Sagima]

I've tried prepopulating using copying or backup/restore when I've used DFS to pretty much no success. Letting windows do it itself (admittedly with a massive 60GB staging quota) has kept it happy ever since

[DavePa]

Is there is any way of bringing the servers together even over a weekend or something? That's how we planned a similar task (although in the end it never happened). If you speak to backup companies they usually recommend:

 

- both servers plugged into same switch

- both servers on same LAN segment at same site

- both servers at same site but dfferent LAN segments

- portable storage

 

Having the servers at different physical locations is the slowest and riskiest way of doing it

- use

[Trapper]

I was going to, but I still need the network in both sites online. It'd be too much of a faff.

 

TBTB have decided a slow network is better than a flakey partial one!

 

It's actually running quite well, I think I've got the staging quotas set about right.

 

Finally got time to set Sites and Services up properly for proper failover and logons on a local DC instead of everything relying on an internet connection!

 

I found a nice tool to monitor it too:

 

[birchanger]

My understanding is that an initial Robocopy before you set up replication is not only acceptable, but the way that Microsoft recommend you do it. There is a caveat: Robocopy has had bugs: in particular its handling of timestamps has been iffy, which can mean that files are seen as being changed when they aren't. For that reason you need to make sure that the host doing the Robocopying has all the right updates. There are MS pages listing DFS-R updates that include the Robocopy ones.

 

Another thing to consider is the size of your staging area. The default it 4GB but a sizing rule of thumb is large enough to hold the biggest 32 files. In our case we had single files larger than our staging area. Our implementation has been rolled back: our rushed (and therefore unplanned) attempt to introduce DFS-R may have lost us data, so read up, plan, test - and back up.

[Trapper]

Seems to be going very well the smaller shares of up to 45GB each have replicated fine, and the large two are well on the way.

 

I've set the staging quote at around 50GB, I read the best practice is just larger than the four largest file sizes combined which would some DVD ISOs in my case.

 

I've checked the file counts and everything has made it so far!

 

I'm lucky that I have a good 100Mbps dedicated internet line between the sites and a couple of days when no one is in to use any bandwidth.

[john]

So you pre-stage with a robocopy with the correct switches to ensure IDs match, then do a check on the files, add it to the rep group and then it will do an initial sync which checks them, validates and then updates / changes what's different (if anything) then it completes that moves anything wrong to pre-existing in the DFSRPrivate folder (you can then put it back / delete it etc..) and then off it goes as normal. Whilst this is happening I'd only let it replicate and not be a discoverable target as users will impact that working if they can discover and use it and tears will occur.

 

For the Robocopy - https://technet.microsoft.com/en-us/library/dn495044.aspx helps with that

 

Staging area is the top 32 files if using a new OS:

 

https://blogs.technet.microsoft.com/askds/2011/07/13/how-to-determine-the-minimum-staging-area-dfsr-needs-for-a-replicated-folder/

[Trapper]

Just using the DFS replication wizard to do it. It's already about 50% of the way there, by tomorrow morning it'll be done and I can test write back.

 

My big problem is what to do?

 

I assume if I used a shared DFS name the directory will know which local file server to use based on your IP address as that's how the domain controllers work. I've got the sites and IP transport links all setup.

 

My major problem will be changing peoples home directories will probably break their offline sync on their laptops. So for the time being accounts that are only being used at the new site I might change their H: drive and GPO drive maps to just \\NEWSERVER\Share$.

 

Wait until it's bedded in and get everyone's staff laptops back during the summer, and wipe all the workstation profiles to use a named space. I need to have the laptops back anyway to move Sophos SafeGuard from a locally hosted solution to the LEAs centrally managed one. I CBA to support it any more, it's a pile of pap!