DR PLAN / Help (basics)

[bran2235]

Hello everyone-

I'm Devising our first round of a DR plan that I need some pointers / suggestions on:
Here's our setup (pretty simple)

Single Forest / Single Site
2 DCs- both at our "Primary Hub" / Same physical location
Both DCs are 32bit
DC1 (AD-Integrated DNS, GC, ALL FSMO ROLES)
DC2 (AD-Integrated DNS, GC)

I am perfomring SYSTEM STATE BACKUPS nightly on both DCs
We have a remote DR site with a bonded T1 (3MB) connection to our "Primary Hub".

I need to make sure I can bring up our Domain (at our DR SITE) in the event that our "Primary Hub" goes down / flattened in a disaster scenario... The main reason is so that our Exchange Guys will be able to successfully complete their DR Plan- we need a DC in the DR site....

DR Site has:
- 3MB Connection back to Primary Hub (now)
- Totally different Hardware (64bit Itanium) than what is at our Primary Hub
- I will be able to use this hardware, and I have access to all software needed
- SYSTEM STATE BACKUPS from both DCs

Should I build a DC at the remote DR site now as an additional DC to the domain? This way, replication will be there... (help)...

-What about load on the remote DC at the DR Site? I don't want users to depend on it? See where I'm going?

Can someone guide me in the right direction here? Is this a somewhat good idea?? Suggestions?? Does this make sense?


Thanks for any help!!
Brandon

 

[TNGPicard]

Based on what you've said, and provided that you have the resources and budget for licensing, etc I would _probably_ start with setting up that machine in the DR/remote site, make it a GC and put it in with integrated DNS. Set the DC up in a separate site under sites & services, put the server there and change the replication to once every few hours (so it will lag behind a bit and not suck up all your bandwidth but if you have a small network/directory it wouldn't be to big a problem), just don't make changes to your directory at the DR site because they would take a while to come over. If you run DHCP make sure you have a copy of at least your configuration over there too along with any other small things (even if they aren't active).

If your primary site gets completly obliterated things wouldn't necessairly fail over instantly but you'd have a good online copy of your AD (even if a few hours delayed) and you'd have to seize your FSMO roles.

Just my opinion from this black hole here.

 

[bran2235]

ok- Thanks a lot- I like the idea. I've never worked in an environment with more than one site... so, here's what I did to start:

-Created the new site;
(don't have the server up in order to add it though)

Question:
Isn't the default replication between sites 180 mins? How do I adjust this so that (per your recommendation) replication happens every couple of hours / between my original site and the new site?

Thanks!
Brandon

 

[TNGPicard]

Brandon -

You can adjust your replication schedules through Sites and Services. You can leave it at the defaults but depending on what has to replicate and whats going over your T1 you don't want to suck up all the bandwidth for that.

TNGPicard / Mark

 

[bran2235]

Ok, couple questions (again!)...

I know I need to adjust replication between original (SiteA) and new site (SiteB)... I know this is easy using the GUI-

However, I keep seeing stuff about a SiteLink Cost...

-how does this apply to this two site setup?
-If there is only one link connecting to my remote / DR site- can I just give it a 50? Can you help me understand this?

Thank you for your help!!
Brandon

 

[TNGPicard]

With only two sites, you don't really need to worry about site link cost because there is only one route between the sites so whatever value you put in will be the route with the least cost.

Site Link cost is basically a way for you to help the replication systems figure out which site to replicate with when you have multiple sties and multiple paths between sites. If you have links from Site A to Site B and Site B to Site C and Site C to D -- all of these links are say T3's you could give them all a cost of say.....3. Lets say that you then have a link from site A to Site D but it is some type of slow frame relay -- for some app that only A and D use that you're routing over that link some how, maybe with a cost of 35. If Site A needs to replicate with Site D the system looks at the "path of least resistance" - i.e your site link cost -- going A-B-C-D at a cost of 3 per link would give you a cost value of 9, AD won't try and replicate over that slower link with the cost of 35.

Mark L. / TNG