Hi,

Exchange 2013 latest cumulative updates and service packs include all the changes from previous updates and are full builds of the product. There is no reason to install the previous cumulative updates or service packs to get the latest features. Microsoft recommend upgrading to the latest cumulative update or service pack instead of upgrading CU/SP one by one.

Best Regards.

We have Exchange Server 2013 (Build 847.32) at CU4 and was put into production in 8/2014 on a Windows 2012R2 server. It has been working fine since that time but we are considering getting it updated to the latest CU9. It has all Exchange roles.

1. Is it advised to upgrade it even though there are no issues?

2. If so, can we go straight to CU9 from CU4, or do we have to install some other CUs first?

Please advise.

Thank you!

Here's some notes concerning the upgrade from the MS Exchange Team Blog: http://blogs.technet.com/b/rmilne/archive/2015/06/16/exchange-2013-cu9-released.aspx

As far as the question about going from CU4 to CU9, the answer is "Yes", you can go from 4 directly to 9.

We have Exchange Server 2013 (Build 847.32) at CU4 and was put into production in 8/2014 on a Windows 2012R2 server. It has been working fine since that time but we are considering getting it updated to the latest CU9. It has all Exchange roles.

1. Is it advised to upgrade it even though there are no issues?

2. If so, can we go straight to CU9 from CU4, or do we have to install some other CUs first?

Please advise.

Thank you!

As B0ndoo said you can perform an upgrade from cu4 directly to cu9.  Each CU is full product install.  I will say it is not generally tested to jump more than 1 or 2 CU's, that's not to say that you will run into issues, but there is a small chance that you might encounter something since this is something the Exchange team doesn't necessarily test.  

As for your first question, I would say it absolutely is advisable to patch to the latest version. The main reason to patch would be supportability.  Microsoft technically only supports the 2 latest CUs meaning currently CU8 and CU9 are the only supported ones.  They also sneak in some new features and new security stuff into the CU's so it's always good to patch.

Ok - sounds like we should maybe just go to CU6 first and then to CU8 then to CU9... or something similar.

Thank you for your reply.

I would rather go to CU9 directly after going through the tests but hopping from CU4 to CU6 to CU8 and then CU9 would be more pain than fixing any issue that you get with CU9 and chances are very less compare to multiple hopping, if you encounter any issue with any CU's in-between CU4 and CU9 and you would find that issue is getting resolved in CU9!

In your answer, are you stating that you have tested going from CU4 to CU9?

If you are really worried about testing, then it is something that you need to do in your Test environment first assuming you have identical Test environment like your Prod environment, because all environments have different configurable variables.

I believe, in general Microsoft does the QA with standard configurations before releasing this to public ;)