Operating System Safe Mode
Microsoft Windows, Mac OS X and Linux distributions such as Ubuntu and Linux Mint are examples of contemporary operating systems that implement a safe mode (called "Safe Boot" in Mac OS X); as well as other complex electronic devices.
An operating system in safe mode will have reduced functionality, but the task of isolating problems is easier because many non-core components are disabled. An installation that will only boot into its safe mode typically has a major problem, such as disk corruption or the installation of poorly configured software that prevents the operating system from successfully booting into its normal operating mode.
Though it varies by operating system, typically safe mode loads as few executable modules as possible and usually disables devices, except for the minimum necessary to display information and accept input. Safe mode can also take the form of a parallel "miniature" operating system that has no configuration information shared with the normal operating system. For example, on Microsoft Windows, the user can also choose to boot to the Recovery Console, a small text-based troubleshooting mode kept separate from the main operating system (and can also be accessed by booting the install CD), or to various "safe mode" options that run the dysfunctional operating system, but with features such as video drivers, audio and networking disabled.
Safe mode typically provides access to utility and diagnostic programs so a user can troubleshoot what is preventing the operating system from working normally. Safe mode is intended for maintenance, not functionality, and provides minimal access to features.
Microsoft Windows' safe mode is accessed by pressing the F8 key as the operating system boots. Also, in a multi-boot environment with multiple versions of Windows installed side by side, the F8 key can be pressed at the OS selector prompt to get to safe mode.
An equivalently minimal setting in Unix-like operating systems is single-user mode, in which daemons and the X Window System are not started, and only the root user can log in and which allows an administrative account commonly known as "root" to have its password reset without knowing what it is first. On Mac OS versions 6, 7, 8 and 9, a similar mode is achieved by holding down the shift key while booting, which starts the system without extensions. In Mac OS X holding the shift key after powering up activates Safe Boot that has background maintenance features (Besides the mode selection, it runs a file system repair, and in Mac OS 10.4, it disables all fonts other than those in /System/Library/Fonts, moves to the Trash all font caches normally stored in /Library/Caches/com.apple.ATS/(uid)/, where (uid) is a user ID number such as 501, and disables all startup items and any Login Items) and can reset an administrative accounts' password. In Windows, safe mode with networking, one of the variations of safe mode, can be used to troubleshoot network issues. In OS X, Safe Boot always includes networking.
Read more about this topic: Safe Mode
Famous quotes containing the words operating, system, safe and/or mode:
“I think there are innumerable gods. What we on earth call God is a little tribal God who has made an awful mess. Certainly forces operating through human consciousness control events.”
—William Burroughs (b. 1914)
“Delight at having understood a very abstract and obscure system leads most people to believe in the truth of what it demonstrates.”
—G.C. (Georg Christoph)
“Philosophy is like trying to open a safe with a combination lock: each little adjustment of the dials seems to achieve nothing, only when everything is in place does the door open.”
—Ludwig Wittgenstein (1889–1951)
“In most cases a favorite writer is more with us in his book than he ever could have been in the flesh; since, being a writer, he is one who has studied and perfected this particular mode of personal incarnation, very likely to the detriment of any other. I should like as a matter of curiosity to see and hear for a moment the men whose works I admire; but I should hardly expect to find further intercourse particularly profitable.”
—Charles Horton Cooley (1864–1929)