High CPU Usage by LSASS.exe when installing Exchange Server 2013

exchange-2013lsasswindows-server-2008-r2windows-server-2012-r2

We have a Windows 2008 R2 DC and we are installing Exchange Server 2013 (New installation) on a Windows 2012 R2 Server. During the installation I noticed it is getting stuck after completing 18% or 19% during the ADPreare step. Following are my findings

1) While the installation is stuck, on the DC LSASS.exe is using 100% CPU

2) I have narrowed it down to the series of LDF files (Named PostExchange20XX_SchemaYY.ldf) the installation loads on the AD using the LDIFDE tool.

3) If I run the entries in the LDF file that gets stuck individually, it loads successfully. But when there are multiple entries this issue happens.

4) While the LSASS.exe is 100%, even if I cancel the Exchange Setup the CPU usage does not come down and only way to bring it down is to reboot.

5) Tried running Active Directory Diagnostics performance counters to troubleshoot, but it does not log any data at all.

Any ideas?

Best Answer

First of all, make sure you are running the latest release of Exchange 2013, Cumulative Update 6. You can get it here. It's a full setup package, you can (and should) use it to install Exchange 2013 even if there is no previous version installed.

Then, try to manually run only the setup step which performs the AD schema extension:

Setup.exe /PrepareSchema

If you still have trobules, then there probably are problems and/or performance issues on the domain controller which holds the Schema Master role; try transferring it to another domain controller and running the schema preparation again.