Clustering / Fail over + Web servers + SQL 2008 + Server 2008

[Izi]

Hi all,

Really need some help and direction for my next set up.

I run a couple webservers, and these run simple set ups and are not fail safe. I run Windows 2003, and SQL 2000. Although they run raid (and backed up daily), if one server is down, there is no back up server to take that role whilst down.

I have read in to Windows 2008 and it looks like some impressive kit. I like the new Hyper-v stuff, essentially meaning less need for different servers for different rolls.

Very simple, what i want to know is how do I set up a server to have a fail safe server running if one fails? I want a server which is mirrored on another server and if one fails one automatically takes over. I assume this is possible, but how does it work? Is this clustering? If one server goes down because of a failed HDD, it is taken off line fixed and put back online, how does it re-calibrate with the server which was working while it was down?

Sorry for the very newbesk questions, but I always have stuggled with microsoft jargon and just need some one to speak layman to me and point me in the right direction!

A packet of crips and a pint to any one who helps

Many thanks!

 

[Izi]

snip.

Thanks for the replies both.

I suppose I should maybe explain my situation, and therefore you could possibly suggest something easier / better that I could implement.

Currently I have 3 web servers and 2 mail servers.

What is good about this is that if one server goes down, it only effects 1/5th of my clients as I have 5 separate servers.

Now if I upgraded to Windows server 2008, I could potentially get rid of these servers and run them under Hyper-v. The problem being now if the server went down it would effect 100% of my clients.

The current servers we have set up are nothing special in terms of spec either, duel core, 2gb - 4gb ram, 160gb raided 15,000 scsi disks so are relativly cheap.

I was thinking that I would minimise servers and just have one more powerful setup. IE 8 cores, 16gb ram, raid 10 6 drives. Thus I could dedicated more cores and ram to the web / sql VMs than the mail.

One thing I definatly want to do is upgrade to SQL server 2008 and Windows 2008 as the next set up we do I want to last for 5 years. Have to move with the times and that!

Thoughts?

Cheers.

 

[Izi]

Personally given that setup, I'd probably virtualise it all but run it on two reasonably powerful boxes (at least quad core with 8GB RAM, maybe 2x Quad cores). The downside is to get the ability to move the VMs between the two nodes you'll need to put them on some kind of back end storage (NAS or SAN of some kind). You should be able to do it with some decent HP hardware and get substancial change from £10k easily...depends if that fits your budget...

you mean run two boxes one which is fail over if one fails?

Not sure of budget yet... been looking at dell and i can put together an amazing spec for 4k + VAT - so would need 2 of these to 'cluster'

 

[Izi]

And a back end "shared" storage.

Ok..

So a couple of questions: If a server A goes down, server B takes over. When server A is brought back online how is it re-calibrated. Files / Databases etc?

Why would i need a separate storage device? If i had raid 10 4x450gb hdd that woud give 900 gb of sotrage which is more than enough for us.

 

[Izi]

The virtual hard drives for the server are stored on shared storage, otherwise it one node went down, the data would not be accessible (as the hard drives would be down as well). The memory and cpu resources come from the nodes

this has confused me, mainly i think, because i dont understand how nodes work.

I am thinking of the set up like a mirrored pair of disks which is obsiously wrong.

can you explain to me a little about nodes?

Are you saying there would be three components - two servers and one central storage device?

 

[Izi]

Depends if you want to buy those features. ESXi is free.

does esxi just do what hyper z does in 2008? if so whats better about esxi?

edit: just looked at their website. so its a small program (32 megs) which runs on a server which in turn virtualizes OS's?

IE you install vmware on the server then the OS in VMs on top?

Where as hyper-v needs windows first before virtualizing?

 

[Izi]

I think you need to take a step back and go and do some serious reading about clustering over on Microsofts site, or head to VMwares site and have a read about esx and it's requirments. Don't jump into this lightly or based on a thread on a forum, you are getting into some quite complicated territory which is fine when it works but can be interesting if it fails. I would want to be very confident in what I was doing if I was deploying this for a customer base.

I agree 100%, i have 4 months before I need to do anything - plenty of time to learn.

I often find learning from others much easier than reading through microsofts jargon, therefore forums are a great resource.

If anyone does have useful links I could start reading on that would be good.

I am contemplating paying for a techy for a day or so to give me a kick start!