We have DL380G4 servers and trying to install rad hat linux AS3.The servers are connected to TFT5600(integrated keyboard & mouse) via HP CAT5 0x1x8 server KVM console switch. when we start graphical installation the display is reporting the following error "selected resolution is not with in recommended range of operation".The display screen is resized to center of the display panel.if we connect this TFT(integrated keyboard and moune)directly with the server,the display does not report this error and every thing work fine.Does anyone have suggestion to resolve this issue? is this due to KVM.if yes then how can we overcome on this problem?

This can occasionally happen with KVM switches. Problem is that often the maximum resolution/monitor freq settings are different for the KVM than for the monitor. Check the documentation for the KVM switch to find if it has different limits, if it does then you may need to use the lower of the two settings.