See the topic from the BMC Remedy ITSM Deployment online documentation.
If you are using the Release Management module from BMC Change Management, do not install the mid tier on the computer where BMC Remedy AR System server is installed. This will enable you to avoid the HTTP server errors caused by the unsuccessful download of files used by the Release Calendar.
The hardware requirements for any given environment depend on the size and amount of activity you expect. This section describes minimum requirements.
Perform an analysis of your organization's needs to determine the hardware requirements for your installation.
The minimum requirements given are intended for use in non-production, proof of concept, or small development environments. Using the minimum requirements, you can install BMC Remedy AR System, launch your browser, and view the BMC Remedy AR System sample application without further customization on a Windows-based server.
The following requirements are for Windows-based servers. UNIX-based servers have comparable hardware requirements. They do not include database minimum requirements, which vary by vendor. See the database vendor's documentation for recommended database system requirements.
Hardware and software requirements are listed in the Product Availability and Compatibility Matrix available at http://www.bmc.com/support/product-availability-compatibility.