Microsoft SharePoint Foundation 2010 and Microsoft SharePoint Server 2010 do not offer the option to configure the location of the SharePoint diagnostic trace log files during installation. This can, however, be configured through Central Administration or through a simple PowerShell command after installation.
With the default SharePoint configuration, the SharePoint diagnostic trace logs are stored in the 14 HIVE on the local hard drive of each SharePoint server in a SharePoint farm (C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\LOGS). If you are not going to store the diagnostic trace log files on a different drive, it is recommended to leave the default location. However, you may wish to store them on a different local hard drive for storage space or other considerations.
When deciding where to place the SharePoint diagnostic trace log files, it is important to remember that they must be stored on a local hard drive. SharePoint does not support storing the diagnostic trace log files on network storage. Also note that the specified directory location must exist in the same place on all SharePoint servers in the farm.
To configure the SharePoint diagnostic trace log location through Central Administration:
Open Central Administration for the SharePoint farm you wish to change the storage location for
In Central Administration, browse to Monitoring and then to Configure Diagnostic Logging under Reporting
Specify the Path to the storage location under Trace Log
To configure the SharePoint diagnostic trace log location through PowerShell:
Open the SharePoint 2010 Management Shell (PowerShell) on one of the servers in the SharePoint farm
Enter the following PowerShell command specifying the log location:
Either method produces the same result and is only required to be once per SharePoint farm, regardless of how many SharePoint servers are in the farm. You do, however, need to ensure the configured location exists on each server in the SharePoint farm. After configuring using either method, the change will be reflected immediately.
I found you can change the INDEX LOCATION during installation.
However, the DIAGNOSTIC LOGGING.....I haven't found. This seem to be done after only.