I ever install Ubuntu without swap partition or file. Is that OK or must I create one?
The Swap partition is necessary. However, IF the PC that has been installed on has large amounts of RAM, the swap partition may be used less. System itself will deal with RAM/swap usage. Should be no real need to tinker. With small RAM amounts, swap partition is crucial! In this situation, swap is needed so that the system has a 'place to go' once the RAM is filled up. Remember that swap is going to behave as if it is RAM, meaning random access. That means data is constantly in/out of RAM/swap while applications and the OS itself runs. Hope this helps Craig