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If one server is down entire farm is unreachable?, in the Citrix XenApp / Presentation Server forum on BrianMadden.com

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Adam Towne posted on 10-09-2008 12:35 PM
I thought I had fixed this issue earlier, but I was wrong. If the server that is hosting our datastore goes down for any reason, our entire farm stops talking. I can no longer reach it with the AMC that is installed on my local machine, our web interface server stops displaying all applications from that farm. Luckily existing connections remain in place, but I cannot have my farm dependent on one server to function. Any ideas what I may have done wrong?

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Brian Moritz replied on 10-09-2008 1:02 PM
Well if the database server is down you can't open CMC/AMC to the farm. The webinterface should and the farm as a whole still work & accept new connections. My guess is in your webinterface farm configuration your only have that one server listed. Manage the webinterface and select manage server farms, edit the farm. There only that one server in that list?
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Adam Towne replied on 10-09-2008 1:43 PM
All the servers are listed under the web interface config. Now, the web interface server is located in a DMZ and we just noticed that our XML port was blocked to all servers except that 1st server, but that was fixed a few weeks ago.
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Brian Moritz replied on 10-09-2008 1:50 PM
What error you get in the Webinterface when that one server is down? It's got to be something to do with that XML communication, it's not able to communicate etc. Name resolution working? Can you telnet from the Webinterface server to the other servers on the XML port?
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Adam Towne replied on 10-09-2008 2:33 PM
I do not get an error. We have two farms, and when that one server goes down, all of those applications just disappear. Also, I can reach the one server with telnet, but not the others. Time to go bug the network manager again. I will let you know how it turns out.

Also, if that server goes down, am I completely unable to use the cmc/amc or is there something I could do to allow me to manage the farm if the datastore was unavailable?
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Brian Moritz replied on 10-09-2008 3:14 PM
No, if the datastore is down you can't manage the farm. The datastore is the 'authoritative' source for the farm configuration. When you open the CMC you connect directly to and edit that database. The farm will still work though using the local host cache. You can also still launch the AMC and manage the webinterface. That's not dependent on the database.
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Alan Osborne replied on 10-11-2008 11:39 PM
Hi Adam,

You haven't really explained what type of server you are using for your datastore, but you should have the datastore on a dedicated SQL server, not on a CPS server. As well, each of your CPS servers should be configured for a direct connection to the datastore.

Provided you already have the datastore on a dedicated SQL server, the only other thing you can do to make the datastore highly available is to cluster the SQL server.

Having said that, if you can stand a few minutes of downtime for your datastore, then setup a standby SQL server ready to go (for instance, you could use a file server or DC with a standby instance of SQL Server 2005 Express and enable the instance in a DR scenario). Provided you have good backups of the datastore, you can quickly restore the datastore to the standby server.

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hans straat replied on 10-12-2008 2:19 PM
sounds a lot like your database is mcaccess database on the first citrix server. Migrate the database to a SQL database server preferable a high availability server or like Alan states if you need high availability create a clusterd SQL database. You can find what type of database you use in your mf20.dsn file (program files\citrix\independ management architecture). There are white papers how to move a mcaccess database towards SQL database. But... you forgot to tell us what kind of database server your using so these are wild guesses :)

Hans Straat , The Netherlands
CEO www.datacrash.net

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Adam Towne replied on 10-14-2008 1:53 PM
I am fairly certain they set up an SQL express database, but I do not actually see any way I can confirm that.

I am also looking at the admin guide for migrating to a 2005 SQL database. However, I want to double check with people who have done this in real life. Can I migrate a live farm to sql 2005 without a rebuild?
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hans straat replied on 10-14-2008 3:21 PM
Like I said before in the mf20.dsn file is your connection that shows how you are connected.
On the server check what SQL database engine runs there. How to migrate sql msde to sql full don't know I know you have to rebuild the mf20.dsn after migrating however. Here is a mf20.dsn example from one of my test servers.
[ODBC]
DRIVER=SQL Server <
UID=straath
WSID=TS2008_02
APP=Citrix IMA
Trusted_Connection=Yes
SERVER=TS2008\CITRIX_METAFRAME <
Description=citrixdb

Hans Straat , The Netherlands
CEO www.datacrash.net

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Adam Towne replied on 10-15-2008 2:03 PM
I am sorry, I should have been more clear. Yes it is using SQL server, but I was not sure if it was an express edition or not. However, now that I think that question through the answer is obvious.

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