DFS on a school network - is it overkill?

[i4004]

I have had it suggested that Microsoft DFS on a school network (say one site 500 pupils, 80 staff) is overkill - and could lead to more problems that it solves. Any opinions?

[MacGeek]

What do you actually plan on hosting on the DFS?

[Achandler]

We had DFS, and I suspect but maybe due to dubious setup (a lot of stuff was here) it caused problems. Ignoring the obvious problem of sometimes it takes about 15 minutes to replicate etc, so in theory a student could move from one room to another and there work not be there.

 

Ours also started to delete new files instead of replicating them, well technically it replicated but it replicated the out of date server... These deleted files were though happily stored on both servers in the shadow copies, so there was a really odd thing happening, so yes we binned replication, more hassle then it was worth to us. That said he had been happy (if not slighly annoying when replication was slow) for atleast a year or so, and as I said the person who was here when it was setup can only be described as inept.

 

Ours was home drives replicated.

[localzuk]

I'd say that DFS is a step in the wrong direction now really - it is at too high a level, and leads to a bunch of weird issues (like those Achandler had, I had similar issues when I set it up at my last school). Instead, I'd say look at a lower level replication such as replication between 2 SANs.

[Bezwick]

We have been running DFS here for two years now. Each night our DFS is replicated to a backup server in a remote part of the school hence if we ever have a problem in our servers room that server can take over with just a few script changes. (its also DNS, DHCP and a Domain controller). We do it mainly for redundancy and backup but its never even blinked in two years and our school is similar size to yours. Some may say its overkill, but i found it really useful. The only problem we had was with mapping homedrives, they didnt work very well over DFS so we just mapped them normally, everything else works great.

[zag]

Total overkill....

 

We just have a 2nd file server that I sync each half term.

 

If the main one ever went down I would simply change the server name from "fileserver" to "fileserver2". Easy.

[Netman]

Yep, overkill indeed... volume shadow copies and a decent backup routine would be adequate IMO...

[chazzy2501]

Yep, overkill indeed... volume shadow copies and a decent backup routine would be adequate IMO...

 

Agreed. For a school with a limited budget this is the apt solution. If your a corp with tens of thousands of pounds of business an hour then go for more.

[Domino]

Guys, you should add DFS-R is what you're talking about here.

 

DFS will allow you to have multiple file paths/servers served under one root path - transparent to the user. The parts are totally usable separately.

 

Also, those of you who've had trouble, the 2008 DFSR version is *much* more reliable, and speedier - upgrading existing rep groups to use it is a pain, but worth it.

[SYNACK]

No, it is totally not overkill, just don't use it for replication. If you change servers/where docs are stored you don't want to have to change all the links, scripts, mess with cnames and reg entries if you are not pulling the original server.

 

Use DFS but only to provide a unchanging path to stuff so that it can be hot swapped in an instant as needed.

 

DFS replication, no, use something else.

[3s-gtech]

Using DFS-R here, 2008 version (two R2 servers). Only been running a few months, but has been pretty good so far. I built it from two homebuilt servers, so not too much investment, but it handles a very heavy load pretty happily. I went for it as a failsafe in case one server failed.

[TheScarfedOne]

Seconding comments made earlier really - it is important to define the difference between DFS and DFS-R here...

 

DFS - lots of shares on different servers accessed via one path e.g. \\server1\share1, \\server1\share2, \\server2\share4, \\server 3\share4 all become \\domain\network\share1, share2, share3, share4

 

DFS-R - yes, multiple copies of each share across different servers. Earlier versions of DFS-R could be a real pig. SVR08 and 08 R2 have majorly improved this.

 

Overall, Id recommend any setup uses DFS as it gives you the transparency. No users need to know what server the files are on, you can move servers easily, just change the paths etc. Can make life a lot easier.

[chazzy2501]

Yes, sorry DFS-R is overkill. DFS is a cunning way of obscuring network paths that end users don't need to see. Set with the correct ACLs for all users one DFS can contain all the shared resources a user needs.

[jamesfed]

We have it running on Server 2008 R2 and it works like a charm – much improved over plain old 2008/2003.

Main reason being is 2x SANS are expensive but 2x storage servers are much less so – especially when they in turn host multiple virtual machines.

Our entire server strategy has in fact been based around the idea of replicating data using the tools in modern server operating systems and using a rock solid backup system.

Even our virtual desktops run without a SAN

 

However…..having said that we are about double in size to your school and have a very high expectation of up time (we run 24hr systems thanks to our remote access) – having things like DFS and replication allow us to take a server offline for windows updates for a hour or so while everyone just goes on using the replicated server – this way we get very little service downtime each year.

 

So for some schools – yes it maybe over kill so long as you have a solid backup/recovery plan and your staff don’t expect things to work 24/7.

[jhothersall]

I had DFS on my server, completely pointless, it stopped working and caused a lot of problems. I wont be using it ever again !!

[sonofsanta]

DFS-R mucks up VSS as well, at least on 2k3.

 

DFS itself, though, we use and is brilliant - apart from getting both file servers showing up under a single UNC path (to the point where I often forget which server stuff is on) we have a slower, fatter server which replicates everything nightly via robocopy. If anything ever goes wrong with a main file server, we can quickly switch the targets in DFS and apart from running a bit slower, no-one really notices that one of our main file servers is down.

 

So DFS yes, DFS-R, not unless you enjoy mental anguish.

[pete]

We use DFS and (to a more limited extent) DFS-R. It works well (2008R2 and 2003 mixed, until I retire a server).

 

Vital mostly read-only stuff is replicated, but everything is accessible under the DFS Root, which means write-once config files and trivial server swaps.

 

But like most things, if you don't set it up correctly it'll perform like a chocolate teapot. RTFM isn't enough, you need to go look through the best practise guides as well, and here's: Browse by Tags - Ask the Directory Services Team - Site Home - TechNet Blogs a good start.

 

Given that an installed-from-scratch 2008 domain is using DFS-R for hosting SYSVOL, it's not like it doesn't work. (Yes, FRS is in maintenance mode and you really need to get off it - The Case for Migrating SYSVOL to DFSR - Ask the Directory Services Team - Site Home - TechNet Blogs).

[soveryapt]

I have 2 x 2008R2 servers that I use DFS on to ensure (as has been previously stated) that if I need to make a move then the move is transparent to the user end of things and it limits down the number of things I need to change to get things back up and running (theoretically - I've not got around to just turning off the PDC yet to) should the PDC fall over ..

 

I tried to use it on 2003 R2 when I had it previously but it was quite hideous, however 2008 R2 does seem a lot more stable. If you have more than one server it's useful as you just have the \\domain.local\ style address over \\server1 \\server2 etc style address.

 

All in all, I find it works well, but only on 2008 R2 not 2003 R2.

[Davit2005]

I was thinking about DFS for Start Menu redirection at least so they could use the local apps if the server with the Start Menu share goes down.

 

Not sure if it would be a good idea, I did initially try and redirect to the NETLOGON folder but something happened after a server issue and everyone lost the Start Menu so I moved it to a Read Only share on another server.

[mthomas08]

2008 R2 setup here with Replication, although I some what agree on Overkilll to me that school specific. We simply can not hide with our Home drives here and we have suffered failure servers which had to be sorted out/replaced. We had to resort to the backup which sadly failed on the last one (meaning we lost a days worth of work). This actually caused a lot of problems for Staff who updated important documents and students who actually finished important course work ready for exams.

 

So we had SLT turn around and say how do we change that problem, with such a demand for the data now... we had no choice but to implement something. So we resorted to replication which actually works with no issues so far and we use our second server to run the daily backup. We also do daily restorations on that box and the data is replicated almost insantly.

 

Some may say Overkill but for us, that word changes very quickly to "Much Needed". Our previous home drive server was a pile of..... (was purchased against my advice because we got more space out of it and was cheaper). As a result of that failure (for about the 4th time as well) they told me to get some thing in quick which did the job and I had little time to research implementing replication.

 

 

At the end of the day it works, works better then before, it doesnt seem slow what so ever and now we have the ability to switch between one server and the other in the event of a critical failure. Although some will say "other solutions" or "Overkill" what we have had to go through wouldnt at all seem like overkill.

 

Strangely enough that word pops up a lot, our previous Home server was classed as overkill 4 years later that server is on its way out. Our new Exchange server was classed as overkill yet it still is using about 75% of its memory and the HD space required has gone through the roof since migrating from 2003 - 2010. So will always be school specific.

[Bruce123]

I had DFS on my server, completely pointless, it stopped working and caused a lot of problems. I wont be using it ever again !!

 

We use DFS for all our staff shared folders, one network drive/DFS Root with DFS links to 4 different servers, very useful and simple.

 

Haven't used replication part of DFS (then call FRS) for a while (yes it broke but the servers were W2K and apparently DFS is more reliable with 2008 R2). We actually used it for roaming profiles to speed up logins (4 sites and one replica per site).

[eean]

It's also useful if you are installing software via active directory. You can have a replica of your MSIs on a couple of servers and when an IT suite switches on and 30 computers try to access the same file, it's automatically distributed.

I'd say it's best for read rather than write. Not sure why you'd want to use it on home drives, except to provide backup/instant fall-over.

[Bruce123]

It's also useful if you are installing software via active directory. You can have a replica of your MSIs on a couple of servers and when an IT suite switches on and 30 computers try to access the same file, it's automatically distributed.

I'd say it's best for read rather than write. Not sure why you'd want to use it on home drives, except to provide backup/instant fall-over.

 

My guess is just as you said, though I wouldn't call it backup, resiliance is a better term to use (analogy being multiple drives in RAID are there for resiliance rather than backup).

 

There could be another reason, if the school is split across >1 sites with slow inter-site connectivity, having a DFS replica at each site would allow the home drive to automatically connect to the DFS replica on the local LAN (rather than going over the slow WAN link). They could then logon at any other site and continue working (as long as the changes to files replicate in the time it takes for them to get over there and logon).

 

One problem with DFS replicas is that opening a file from one replica doesn't lock it on the others. Should be OK for home drives (if the user doesn't logon at more than one site at the same time), but is no good for shared folders.

 

I agree that replication works best when the replica is meant as a read-only copy.

 

Regards,

 

Bruce.

[Jollity]

We use DFS-R for replicating just about everything between our two main 2003 R2 servers: home drives, shared drives (read-only and write). Then DFS to provide links that direct each client to one or other server. We started using this setup with FRS, which did not work well at all with this volume of files. However I have had very few problems with DFS. There is sometimes a short delay before replication occurs, but it rarely causes an issue. There was a confusing issue recently with videos produced by powerpoint not being replicated as they were marked as temporary files. But most of the time I can forget it's there.

 

The plan is redundancy to allow us to manage for a significant time after a complete server failure. It was used instead of RAID, which I think was a mistake. It has been useful several times but never really tested for an extended period. The fail-over is not as good as I would like because when a server is down a client will only fall back to the other after a significant timeout.

 

I also use DFS-R to provide robust copying of backups from outlying servers to a central server to be written to the backup disks.

Edited April 15, 2012 by Jollity