Exchange 2003 Mirroring Over WAN Link

[dixson]

We have to establish Mirroring ofExchange 2003 Server over a WAN link. This is from a DR perspective. Mirroring should take care of two points discussed below
1>What we are looking for is , both the servers(primary & mirror) should run in active mode. when either fails, other should take over and synchronise when failed server comes up
2>If the link fails, both the servers are working in their own respective geographical sites and registering that the other copy is dead. In this case when the link comes up, the data on both servers should synchronise with each other.
Can windows do this on its own?
Is there a software that can take care of my requirement?
if not , what is the nearest solution?

 

[58sniper]

No.
No.
Double Take will do the failover so that the DR server can assume the identity of the failed box. When the normal server comes back online, you can fail back to it.

Pat Richard, MCSE MCSA:Messaging CNA MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[PScottC]

I am currently working on a project like this. We are running 3 servers in a cluster. 1 active server, 1 hot-standby, and 1 warm-standby. The warm-standby server will be in our DR center across a WAN link. We are using EMC/Legato AutoStart to provide the clustering, and EMC RepliStor to provide the data mirroring to the DR site.

In the case of a server failure, we will automatically fail-over to the hot-standby. In the case of a link failure, we will manually activate the warm-standby. The reason for the manual activation is because A) you can't synchronize exchange DB's between live servers, and B) if someone is performing unscheduled maintenance on a router we don't want an automatic fail-over to the DR site.

Hope this helps.

PSC

Governments and corporations need people like you and me. We are samurai. The keyboard cowboys. And all those other people out there who have no idea what's going on are the cattle. Mooo! --Mr. The Plague, from the movie "Hackers

 

[crobin1]

Nerverfail is another possibility (

http://www.neverfailgroup.com/).

It's still active/passive though. I haven't used it, I heard about it from a friend. If you can wait for the release (in theory late this year/early next), Exchange 2007 will have some low-end replication features built-in.

 

[dixson]

Thanks everyone. I am looking at a solution from EMC. I want to host the passive standby at a different geographical location( a geo cluster).
I have a concern though.
If there is a link failure then the passive server will become online(correct me if I am wrong)as it will loose the heartbeat of active server. At the active end the primary server is still on and the users logon to it. Users at passive end logon to passive as it has come on due to link failure.
How will synchronisation take palce after link comes up?
what precautions should be taken to avoid such a situation?

 

[PScottC]

There are a number of settings to prevent automatic failover to the remote node. Replication should automatically restart when link comes back online, or can be manually pushed. We actually took router reboots, or loss of connectivity to our DR center into account. Failover to DR site will be an intentional act for us...

PSC

Governments and corporations need people like you and me. We are samurai. The keyboard cowboys. And all those other people out there who have no idea what's going on are the cattle. Mooo! --Mr. The Plague, from the movie "Hackers

 

[dixson]

In my situation, IN CASE OF LINK FALIURE, users ta primary site are still connected to primary server. While users in remote site now get connected to the Mirrored server(that is become active because it does not find the primary server due to link failure). in this case database is modified on both primary and mirrored site simultanously by different set of users...
how will replication happen when link comes up?

 

[58sniper]

I think that depends entirely on the product, method, link speed, throttling, etc.

Pat Richard, MCSE MCSA:Messaging CNA MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[PScottC]

The product that we're using would not allow that situation. You would not be able to "merge" the databases together.

PSC

Governments and corporations need people like you and me. We are samurai. The keyboard cowboys. And all those other people out there who have no idea what's going on are the cattle. Mooo! --Mr. The Plague, from the movie "Hackers