What part of the ArcSDE application do you need to be available after installation? What is the business need to perform the installation silently? For many people, it's simply having the ArcSDE command line tools that is the driving factor. Assuming it's the command line tools you really care about and not the post installation tool (for authorizing a GDB or setting up the application service), all you really need is the bin folder which contains all of the executables and associated binaries. For example, an Oracle ArcSDE installation folder would contain the command line tools under: ...\ora11gexe\bin. All that's needed is to install ArcSDE on one machine and then copy/push the bin folder that the installation produces over to other machines remotely using RoboCopy, XCopy, or Copy. Users will then have those tools on their machines, but they will want to add the path to the bin directory to their PATH system variable if they want to use the SDE command line tools without having to start the command prompt at the bin directory.
