Redundancy / Failover Solution

[Hamins]

Hi,

We have a Windows 2003 sever (Xeon 3ghz, 1GB DDR-RAM, 72GB SCSI), that acts as a Domain Controller, file/print server, DHCP, DNS, authentication etc.. Basically, its the only server around, and handles everything. We have around 40 workstations, and all the data (Approx 20GB.) is centrally located on this server.

I'm looking for some kinda redundancy/fail-over solution. ie. If this server fails, the entire load should get transfered to another server automatically. I know that setting up an Additional Domain Controller with take care of the redundacy for all the Active Directory Services. However, will it also act as an redundancy solution for DHCP, DNS, File/print etc ? If yes, how ?

I wonder if the Addtional Domain Controller, can act as the primary File/Print server, and whether the Primary Domain Controller can act as the backup/secondary/failover/redundant file/sever. Can I take care of the file server redundacy issue, using DFS (replication) ?

I hope my question(s) are'nt too confusing.

Edited March 10, 2007 by Hamins

[jeff.sadowski]

I was reading about this not too long ago I think the latest realease supports windows so you might want to take a look.

http://www.backhand.org/wackamole/

[jeff.sadowski]

It says Win32 support was added. So it may support 32 bit windows

[cluberti]

DHCP, DNS, and WINS databases can be replicated or backed up and restored manually, and AD-related data is already replicated to any additional DC in the domain (make sure they're both set as global catalog servers, though). As to file services, that can be taken care of with the second DC via DFS (clustering would also work, but you really shouldn't cluster domain controllers).

[Hamins]

Thanks Jeff/Cluberti,

I don't think I want to get into Clustering... Just want to keep things as simple as possible.

Club, how can the DNS/DHCP be replicated automatically ? or, how can the load-transfer be done automatically. ie. if the Primary server goes down, can the task of DNS/DHCP server be shifted to the Additional Domain Contoller automatically ?

Also, want to know if the Addtional Domain Controller can act as the primary file/print server, and can the Primary Domain Controller act as the fail-over file/print server, in the eventuality of the Additional Domain Controller going down.

Another question : All the user's have Roaming Profiles. Currently, the profiles are in a share on the Primary Domain Controller. I've specified the profile paths in each user's Account properties (\\Primary Domain Controller\Profiles$\username). How do I make the roaming profiles available, even if the Primary Domain Controller goes down ?

[jeff.sadowski]

As long as the DNS service is added to the domain it will automatically replicate as for dhcp you will have to replicate that yourself there may be a export import you could use.

Let me clearify on adding the DNS service to the Domain.

You have to open up the DNS manager and add the domain it will ask if you want to join it to AD say yes and wala its replicated.

Edited March 11, 2007 by jeff.sadowski

[jeff.sadowski]

Clustering wouldn't work so good after thinking about it, cause windows doesn't just use DNS names. They do their own thing.

[jeff.sadowski]

This

"redundancy/fail-over solution. ie. If this server fails, the entire load should get transfered to another server automatically"

describes a cluster.

[jeff.sadowski]

As for file replication

The easiest would be to have a redundant disk array with redundant fiber switches.

We have an EMC disk array at my work.

But if one server goes down the mapped drives will be disconnected your users would need to match them to the alternate file server.

This starts to get in the realm of clustering.

[Hamins]

Then what bout DFS replication ?

[Hamins]

anyone ???

[nmX.Memnoch]

I'm not sure about the DHCP part, but Windows Clustering will work for AD Domain Controllers. The only caveat is that if one node in a cluster is a DC, then all nodes have to be DCs.

If you're only doing a two-node cluster then you can use SCSI/SAS for the shared drives, but I would recommend just going with fiber channel. Dell has some nice entry-level SANs and iSCSI stuff that would work.

Dell/EMC CX3-10c (4Gb/s Fiber Channel SAN/iSCSI, up to 4 nodes)

http://www.dell.com/content/products/produ...;l=en&s=biz

Dell PowerVault MD3000 (3Gb/s SAS, 2 nodes)

http://www.dell.com/content/products/produ...;l=en&s=biz

Edit:

I forgot to mention the Dell/DMC AX150/AX150i. It's a lower cost fiber channel alternative than the CX3 series:

http://www.dell.com/content/products/produ...;l=en&s=biz

Edited March 12, 2007 by nmX.Memnoch

[fizban2]

simplest solution would be be to have a second server that is near identical to the first,

1. Since DC/DNS functions are replicated through all DC's you would be fine if your first DC went down,

2. Having a DFS rooton the first machine and adding the second new server would solve the file issue

3. DHCP can be set to the normal 80/20 split (or more if you need it ) where you split the scope 80% of IPs on one server and 20% on the other, this way if either machine goes down, there are still IPs available for the clients,

[Hamins]

Thanks memnoch, fizbans for your inputs.

I think what Fizban is saying is the best soution...

Fizban, I understood point number 1 & 3. I have'nt really worked with DFS, so could you please elaborate a lil more on point # 2 ?

Thanks

[fizban2]

http://www.windowsnetworking.com/articles_...ile-System.html

an excellant article on DFS, basically with DFS, you will create a "Root" namespace what will encompass all filesshares that you want users to be able to connect to through a single unique path for all users. read the article and let me know ifyou have any questions