When a person is in shock (from any cause), not enough blood and oxygen are reaching the body's organs. If shock lasts more than a few minutes, the lack of oxygen starts to damage the bodyâs organs. If shock isn't treated quickly, it can cause permanent organ damage or death.
The LILO versus GRUB argument is one of those never-ending and passionate discussions that resurface from time to time on various public forums, not too different from the notorious vi vs. emacs or KDE vs. GNOME verbal battles.
GRUB is GRand Unified Bootloader, the default bootloader in Linux. GRUB can be used to boot Linux in single user mode. The single user mode is the restricted mode, that is used for maintenance purposes. In single user mode, the only user available is the root user, and in RHEL, no password is asked for login.