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Tuesday, April 27, 2010
Introducing the new ESE Consultants' Corner
Welcome to the first edition of the ESE Consultants’ Corner! The ENow Solutions Engine is dedicated to helping the greater Microsoft community by providing an online resource of free articles, video tutorials, and advice on the hottest topics in Microsoft technology today. Instead of us always choosing the topic, we wanted to spice things up a bit. Our ESE writers are renowned experts in their fields, so we want you to put their knowledge and experience to the test!
Our writers consult on a daily basis, and constantly receive calls from either customers or colleagues asking about Exchange, Active Directory, Virtualization, Cloud computing, etc. Some of the questions they encounter are common, but others at times are very weird. The ESE Consultants’ Corner is devoted to answering only the really cool questions our writers get asked on a daily basis. We will share with you their answers to the common questions and the not-so-common ones, so that you can benefit and learn from their expertise. The ESE Consultants’ Corner will be devoted to covering a broader range of topics as well as addressing questions that require fast answers. We want to hear from you! Do you have an advanced technical question that you need answered? Do you have a design or planning issue that you want expert input on? Please send your questions to: ese@enowinc.com. This will give you access to the ESE experts and allow you to ask them questions directly. If we encounter a really tricky question, then we might devote an article to it. The rules for submission are simple:
We want you to have a say in the topics we discuss, so email us your questions today! Before we begin the Consultants' Corner, please note Mahmoud's Magdy's updated OCS-DNS calculator below.
The key to a successful Office Communications Server Deployment: The Errata and new OCS-DNS Certificate Calculator By: Mahmoud Magdy I have received lots of feedback regarding the OCS-DNS certificate calculator. Since there was some confusion, I have written this errata for clarification and also made some corrections to the calculator to make it clearer. Please note the following: - You can use the calculator with OCS 2007 R2 only. You cannot use it with OCS 2007 as we have not tested it against 2007. There are no plans to test it in the future, but it might be something we pursue further down the road.
- You can use the calculator for Exchange 2007 and 2010 deployments; there are no differences between both products in regards to the certificate requirements.
- For HLB (hardware load balancers) the calculator will work if you assigned the edge FQDN to the VIPs. It has been tested and will work very smoothly.
- To generate certificate request, use the OCS installer to create the certificate using the certificate wizard, then copy and paste the names generated by the certificate calculator into the certificate wizard.
- Make sure to import the certificate on the same server you generated the certificate request from and export it along with the private key. This is mandatory to be able to assign the certificate to other servers.
We have uploaded a new version of the calculator that has the following fixes: - If you are using a certificate for Exchange and OCS, the certificate common name must be sip.domain.com or whatever the FQDN that will be assigned to the edge access and web conference. (This is a limitation that comes from the OCS that has been fixed in the current release.)
- If you cannot make the certificate common name the Edge Access FQDN, then you can use a separate certificate for the Access Edge and Web Conference Edge.
- We removed the web conference FQDN selection, since it has to match the FQDN assigned to the access FQDN.
- We added port feature, so now you can assign a port and this will help in configuring the web conference edge.
http://support.enowzone.com/Downloads/OCS-DNS-Certificate-calculator-V1.5.xlsx Credentials
Username: enowzone\freetrial
Password: H3althCh3ck First Consultant’s Corner post: By: Mahmoud Magdy Hello! My name is Mahmoud Magdy and I am honored to be hosting the first ESE Consultants’ Corner. For this edition’s post, I chose to answer several questions I recently received that will benefit our readers the most. Q: I am sending a large amount of emails per day and I am afraid of being listed as a spammer. What are the rules regarding spam? A: You may rest easy because you will not be listed as a spammer just because of the large amount of emails you send. In fact, you will not be listed if you send a single spam email to as many as 1,000 or more recipients. The general rule of thumb regarding spam is this: being listed as a spammer is not related to the amount of email you sent, but rather the content of the emails and to whom they are sent. If you are simply sending advertisement emails to your customers then you will not be listed, but if you send advertisements to a mailing list that you don’t own then you are busted. However, if your email system that is sending these types of messages is not secure and properly configured, then you will be blocked. The most common errors include DNS mis-configuration, SMTP banner and FQDN, and SPF solution, among many others. Q: We have an internal application that sends emails using our internal relay connector. Will these emails be listed as spam? A: For the general rules, please see the answer above. In regards to your particular situation: 1. I recommend that your application uses an email address that exists inside your organization 2. Try your best to authenticate the SMTP connection using your application; this will create an authenticated SMTP connection to your relay and it will be safe. Q: My storage guy is doing a RAID X implementation because he told me this is the best option for my storage and Exchange deployment. Do you agree with him? A: Let me preface this by saying that storage guys usually don’t like me. They are very professional and their work is very scientific, so when an Exchange guy comes in and tells them ‘This is how we should do storage,’ it does not go over well with them! I recommend that you design your Exchange deployment using the Exchange storage calculator or your vendor’s calculator, and ask then storage guys to give you IOPs. Don’t worry about the RAID type as long as you get the required performance. Of course your must determine if the deployment option is the most cost effective method and will provide optimum performance. Storage guys really are the best people to tell you how to design your storage, but again make sure you ask for IOPs and not RIAD. Q: I bought a server with 24 cores, but I heard that Exchange will not benefit from it. What I shall do? A: Multi role deployment works well with 24 cores, and can even reduce issues without using the WSRM (Windows Server Resource Manager.) The problem is more with single role deployment and cross talk, but I must warn you that there is a catch: Microsoft testing shows when environments are sized according to Microsoft current guidance, multi-role systems perform fine without WSRM. (I will put a caveat on this by saying that most of the testing was done on 8-12 core systems.) 24 core systems have been low priority, so if Microsoft does not have a linear scale then these systems may benefit from WSRM. One other thing to be aware of with 24 core Intel systems is that most of the hex core (Dunnington) processors are over 1.5 years old. Until the processor vendors release the next round of 4 socket large core processors, you may be better off running a 2 socket Nehalem quad core system over a 4 socket hex core system. Example: In conclusion, today you can run a higher number of mailboxes on the newer 8 core servers than older 24 core servers. I hope our first edition of the ESE Consultant’s Corner was helpful for you. What challenges are you facing in your environment? Need an expert opinion on an upcoming project? Feel free to email us your questions at ese@enowinc.com. I look forward to hearing from you. Until the next post, wishing you faster processors and bigger RAMs… Mahmoud Labels: Exchange Support, Exchange Tips, Office Communications Server R2
Tuesday, April 13, 2010
Exchange 2010 Site Disaster Recovery on a Dime! Part 2: Navigationg the Failover Process
By: Lasse Pettersson, Exchange MVP
In Part 1 of this series I explained how to build a low cost site or datacenter disaster recovery solution using Microsoft Exchange’s new DAG feature. In this article, I will endeavor to explain what manual steps are required to failover to your other site in the event of a disaster.
First of all let’s discuss what types of problems can occur. There are a variety of problems that can happen ranging from simple disk failure to a tornado smashing the datacenter in the primary site. In this article, I would like to address how you would manually activate your backup Exchange server if your primary server’s mother board or disk failed. Next, I will outline the steps to take if you experience the dreaded total site failure. Finally, I will conclude with how to fail back to your primary site when everything returns to normal.
OK, so how do we recover from for example a motherboard failure?
If you find yourself in this situation, you can be sure that your primary Exchange server will be offline and not functional. The good news is that in this situation all your other core infrastructure will be up and working, including critical items like your domain controllers and DNS servers.
The first thing you will notice is that your Outlook clients will still try to connect to the original MAPI endpoint (RPC Client Access Service located on CAS). To quickly rectify this situation, simply change the A record in DNS for the ClientAccessArray to the IP of CAS in the DR site. The Time To Live on this record should be a couple of minutes making the change to a new IP as fast as possible. Another thing you should also consider is the time it takes for DNS replication/updates to propagate throughout the network.
Next it will be time to get the databases up and running on your DR server.
First verify that all Exchange services are running on the DR server. If the services have been turned off this could cause other problems with transaction log replication.
The easiest step is to move all active databases from the primary site to be activated on the DR site. The following command should be run on a server in the DR site, most likely from the Exchange server.
First remove the activation block on mailboxes in the DR site.
Resume-MailboxDatabaseCopy 'mailbox database name\FQDNofaServerinDRSite
Perform this step on every mailbox database you want to activate. There is a chance that databases will mount automatically when resuming mailboxdatabasescopies. You can verify status by running Get-MailboxDatabaseCopyStatus on Exchange server in DR site.
Get-MailboxDatabaseCopyStatus -server FQDNofaServerinDRSite fl Name, Status, ActivationSuspended, ContentIndexState, Activecopy
If databases are mounted and the ActiveCopy is True, then you are done with the activation and outlook should now be able to connect and start receiving and sending mail internally. Next reconfigure services and applications to make Exchange reachable from Internet with SMTP, Outlook anywhere, OWA, Active Sync etc. If you have ISA or other reverseproxy server, reconfigure it to the server in the DR site instead of the server in the primary site. Other services that might need to be reconfigured are autodiscover and InternalUrl in several IIS virtual directories.
If mailboxes don’t mount correctly, you can manually run the following command:
Move-ActiveMailboxDatabase –Server FQDNofaServerinPrimarySite –ActivateOnServer FQDNofaServerinDRSite
Depending how Windows and Exchange managed to handle the crash you might encounter some errors, making the activation a little more difficult. Things that might happen range from the index is not up to date on the DR server or all transaction log files have not been copied to the DR server. The solution is to specify some extra parameters on the Move-
ActiveMailboxDatabase command.
For example, -SkipClientExperienceChecks is good to use when index is not up to date.
If you have not configured AutoDatabaseMountDial on the mailbox server, by default it is set to lossless and there is always a chance that replication have not copied all transaction log files to DR server, then you have to use the –MountDialOverride with a parameter such as BestAvailability or GoodAvailability.
Other parameters that might be needed are –SkipLagChecks or –SkipHealthChecks. You might have to use several parameters together to get databases up and running.
Move-ActiveMailboxDatabase –Server FQDNofaServerinPrimarySite –ActivateOnServer FQDNofaServerinDRSite –MountDialOverride:BestAvailability –SkipLagChecks –SkipHealthChecks -SkipClientExperienceChecks
More information about Move-ActiveMailboxDatatabase is found on Technet: http://technet.microsoft.com/en-us/library/dd298068.aspx
When you have replaced the motherboard on Exchange server in the primary site and replication starts going from the DR site to primary site, you’re good and it’s time to plan the switchover to the primarysite. This is done with the same step as above. Plan the switchover to a time during off hours since the switchover will take a couple of minutes due to the necessary DNS updates, AD replication and time it takes to run the commands above.
Finally, you should run the Suspend-MailboxDatabaseCopy again to disable automatic activation of databases in DR site.
Suspend-MailboxDatabaseCopy -Identity 'Mailbox Database 2036433681\FQDNofServerInDRSite' -ActivationOnly –Verbose
This last step is needed because activation is reset when you do a switchover between servers. Be sure to remember to do this for every mailbox database on your servers.
If you can’t get things started on Exchange in the primary site due to problems with corrupt database or transaction log files, you might have to reseed files from the server in DR site. Use the Update-StorageGroupCopy and possibly with the –DeleteExistingFiles parameter.
Recover from a disk failure is pretty much the same as above but it only involve databases and transaction log files located on the faulty disk. Another cool thing is that you can even test a database switchover in production. To do this, first create a database in the primary site and make a copy in the DR site the same way all the other databases were created. Next create a mailbox in the test database, logon and send some test messages back and forth. Activate the test database on the DR server, edit the hosts file with the FQDN of the CASarrayname and the IP of Exchange in DR site and start outlook again. You should now be able to connect with Outlook to the DR server and use outlook the normal way with disturbing any other users.
Recover from a disaster in the primary site.
This is more problematic scenario, but the steps are basically the same as above. The slightly more complex steps are caused by the fact that you don’t have any servers or network connectivity in the primary site and that your cluster will not have access to its quorum, and as a result it will be in a failed state.
How do you solve this problem?
First you need to make your cluster working.In the DR site, stop the failover cluster service if started and the start it again with the forcequorum switch.
net start clussvc /forcequorum
The next step is to active all databases on the DR server. This is done in the Move-ActiveMailboxdatabase command the same way as before.
You may also have to manually mount the databases.
With a complete site failure in the production site you most likely need to live with the DR site for a while which calls for more actions than just getting your Exchange server up and running.
You also need to get traffic to and from Internet flowing, both mailflow and user access to Exchange. Autodiscover is your friend to update configuration in outlook, so make sure you have configure all URL’s correct.
Overall there is a lot more to reconfigure than just Exchange to do a site failover.
http://technet.microsoft.com/en-us/library/dd351049.aspx
How do you fail back to your primary site after the disaster?
We have forced quorum on our cluster and if we restart the cluster service or reboot the server, the cluster service will fail to get quorum. This is important when servers go online in the primary datacenter since we don’t want to have a forced quorum in the secondary site when servers startup in the primary site.
If everything wasn’t that bad and we could simply power up everything in our primary site, replication should start working again.But you have to do some things like, reconfigure your File Share Witness, restart cluster service on secondary Exchange server, and basically all steps we did to move everything to secondary site but now change everything to point to our primary site again. But don’t rush things here, let Active Directory get to a stable state first and then slowly move things back to normal.
Depending on what state servers are in and what happened you may not want to start Exchange in primary site, but remove it from DAG and rebuild Exchange, join it to DAG etc.
As you have probably noticed, there are lots of variables and therefore it is not easy task to write a step by step guide on what to do for every situation. It would be recommended to write out the basic steps and your configuration information to make the transition easier when you are dealing with the stress of the situation. The best tip I can give to all of you is to learn how things work and play with the various scenarios in a lab. The experience you gain from this will be your best friend when the unexpected happens in real life.
Labels: Exchange 2010, Exchange Tips
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