One of the goals for Oracle Solaris 11 development was to reduce the initial download footprint of the installation images for the operating system. What was once several DVDs in size, a single installation image is now less than 1Gb in size. In conjunction with the new network based package management system IPS, it means that administrators can install something quickly, then tailor it with additional software that meets their needs. Not only have we shrinked the install images, but we've also modernized the installation to make it a familiar experience - particularly for those administrators who are used to installing various flavours of Linux.
If you've taken a look at the Oracle Solaris 11 Download page, you'll notice that there are a number of images to choose from. They each provide a very different experience tailored to suit the needs of different scenarios - whether you're installing the operating system to evaluate it within a virtualized desktop environment, installing it on a headless server, or installing across multiple different systems in your data center. So how do you decide? That's easy:
Installing Oracle Solaris 11 in a virtualized environment
One of the best ways to initially evaluate Oracle Solaris 11 is simply to download the Live Media for x86. This experience is very similar to other Linux LiveCD or LiveDVD installations. You can boot directly off the ISO image to a full desktop environment. This not only gives you a chance to see the desktop, but also can bring up a terminal window so you can take a look at various different technologies like ZFS, SMF, IPS or Zones. While you can of course choose to install it onto an x86 system, another great option is to install it into a virtual machine using software such as Oracle VM VirtualBox.
Installing Oracle Solaris 11 into a headless server environment
After evaluation, administrators will typically install the operating system onto a headless server (one without a display connected to it). For this, it's recommended to use the Interactive Text Installation for x86 or SPARC. This options contains software that is suited towards a server environment and doesn't contain a graphical desktop or any other graphical applications. The installation itself walks the administrator through a series of simple questions in a text based format before installing itself to the system. Administrators wishing to add additional software after the installation can do so using the IPS command line and from configured network package repositories. You may also find that this option is ideal to be installed into a virtual machine if you're trying to develop a proof of concept environment for later deployment into the data center.
Installing Oracle Solaris 11 across multiple systems
While the previous two installations are suitable to install a small set of systems, many administrators will want to scale to multiple systems in an automated fashion. The Automated Installer for x86 or SPARC provides administrators with the ability to automatically install a system by booting it from the media, installing the minimum software needed to get it up to a point where it can install the rest of the software required automatically over the network from package repositories. Most administrators will choose a slightly different route to install multiple systems - by setting up an installation service instead from an already installed and functioning Oracle Solaris 11 system.
In all cases, there's an excellent set of support documentation available by checking out the Installing Oracle Solaris 11 Systems guide. Good luck!