What's the best fault tolerance solution? 2

[SelbyGlenn]

Hi there,

I am very new to exchange so apologies if there is an obvious answer to this question.

I currently have one Exchange 2000 server on a Win2K server. I want to build some redundancy into the network to eliminate the single point of failure. I have a second server which I want to put Exchange on to. What's the best way to set these two up? Do I want a FE/BE solution, load balancing or maybe a hot-spare? Do I have to cluster the servers?

Thanks in advance for any help.


Glenn
BEng MCSE CCA

 

[wyzard]

Hello Glenn,

Cluster options are one way:

the Windows route with Advanced server on two server units and some heartbeat NIC's. This has some good stuff to it and what can really make it good is a SAN that houses the information store. So the servers involved only have one point of reference. BUT - if the the backplane on the SAN goes down there is no quick recovery.

or

maybe something similar to the Legato co-standby server arrangement. Two servers (or more), each with an information store that is updated on the fly from the Active server to the inactive servers. True redundancy with a small amount of time for the transfer of functions if the Active server goes down.

You could also have a "cold" standby server that has Windows Server and Exchange on it but turned off. Then if the primary Exchange server went down, you would turn it on and either:

recover from backup (time intensive, no email flow)or point to an information store that is on a SAN.

Hot spare is possible and has some good points. While similar to a cold server for benefits/detractors, it could also serve as a way to test your full backups, do recoveries as necessary. And if you were testing your full backups on this and had an incremental backup procedure, you could run the incremental recovery to get you up fairly quick.

A recent study indicates that in medium size domains (250 to 2500 mailboxes), only about 9 percent of Exchange servers are clustered and that large domains (2500 and up), only 14 percent use clustering. Some reasons given for organizations not using clustering were good hardware reliability and the cost associated with clustering.

Just thought I would toss in my two cents and I hope it gives you some help.

Wyz

 

[SelbyGlenn]

Thanks Wyz,

Some very useful options there. I've been looking at Legarto co-standy (already using thier Replistor) but it's not cheap! I like the idea of a hot spare with incremental backups. I will definately do some testing along that route.

Cheers,

Glenn
BEng MCSE CCA

 

[dvientos]

Hey there,

I am kind of in the same boat. The info was great but I need more detail on how to configure a second server. That is I want to have a exchange 2000 server that is connected to a SAN. Then I want to have a backup server that I can turn on and be able to connect to the network and re-point to the san where my database is in the event the orginal server dies. Now the issue is that I do not want to have to remove the fiber card and install it on the 2nd server. I want it to have it's own fiber card. Now from what I understand with SAN's you cannot have to cards using the same address. Issue #2: How do I configure the 2nd server? If I give it a different server name my clients will not be able to resolve to the server without us touching(no sms software) each client machine. ANother question is I am going to be using microsoft clustering? I am trying to avoid it because of the cost. But like I mentioned I just want to be able to switch a backup server on and repoint to the SAN. We are willing to accept a 30 min - 60 min downtime on email.

Any help would be appreciated. Also I can't any doc on microsoft on how to do this.

Thanks
Dvientos

 

[wyzard]

Hello Dvientos,

Your questions caught me a little off guard since I was just posting some ideas for Glenn. However, I have a couple of links that may be able to help you (but probably won't answer your questions specifically). One is about MS clustering and the other is a download for a disaster recovery PDF by MS for Exchange.

http://support.microsoft.com/default.aspx?scid=kb;en-us;326271&Product=exch2k

http://www.microsoft.com/technet/prodtechnol/exchange/2000/library/disrec00.mspx

Just as a side note: I will probably use the Co-Standby offering for our environment. I don't have time for a lot of legwork (re-pointing computers to a new Exchange server), in addition to trying to restore an Exchange instance and need a simplified approach.

Wyz

 

[mookie1231]

Check out DoubleTake software by NSI Software. I have it running on Exchange 2000 servers and tested perfectly. We also have it configured to replicate to a remote Exchange server at our disaster recovery site out of state.

~Michael

IT Consultant