IP Failover + Open Directory = The BIG picture?

[vogtstev]

Howdy! I have been working with Tiger server for awhile and have been curious about IP failover. I have read the Apple docs and many of the posts here, but I am wondering about the “big” picture….

I have two servers – both 10.4.7 One of them is running various services including AFP, Web, Mail and OD. I unfortunately at this time do not have shareed storage such as a RAID or SAN. My main goal is to have the second server be idle and have them sync data during the night. There is not a lot of data to sync and it does not change that often. When the main server goes down I want the second to pick up all the services. So, this is what I believe I understand at this point:

•Make sure configs are the same on both machines. I could do this by configing the main server and copying the prefs out of server admin and dropping them onto the backup’s server admin.
•Each have their own IP address and host names.
•All services remain off on the backup server until IP failover turns them on.
•The IP failover setup takes care of the rest by changing the host name and ip address info of the backup server when the main server goes down and then changes it back when the main server comes back up.

Am I understanding this correctly? The most confusing part for me is what to do with OD. Do I run that service as a replica on the backup server or do I sync some directory manually with rsync or something similar?

Any input would be greatly appreciated.

Thanks![b]

[andrina]

If the data that is shared on your server is not a big issue, then certainly an overnight rsync would take care of that. The best plan for the OD is indeed to have the secondary machine running as a replica – this should be running all the time, not set up from the post-acq scripts.

Do note that you are going to have to write the IP Failover scripts to start the services when your secondary machine acquires the primary IP address – this isn’t an automatic function of IP Failover.

Cheers,
Andrina

[vogtstev]

Thank you so much for you help. Just hearing that helps immensly. Two other question comes to mind:

• Do I have to worry about promoting the replica to a master if it takes over?
• When I sync mail and web do I only have to worry about syncing the user folders and Library/WebServer? I cannot remember if there is a single location for Mail. All locations are default. I have not moved them anywhere.

Thanks again!
Steve

[vogtstev]

Hmmm. So would it be better off to have yet a 3rd server hosting directory info? Is there a way to just have the backup server be a master instead of a replica?

For example, is there are directory that can be syncronized with all the account info inside and then have one of the failover scripts activate open directory when the server starts?

how would one normallly sync mail and web if the open directory data doesn’t get synced as well since it rely’s on those permissions?

thanks for you input!

[vogtstev]

Interesting. now OD info really doesn’t take up that much server or bandwidth does it. Do you think that would be a waste of server?

What if the secondary is completely idol – meaning it is not a replia. Is there a way just to sync the directory info and have it be a master. So then the OD service would only turn on it that master fails? Any idea where that is stored?

Interesting, the plot thinkens. Thanks for you help!

[Author]

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