Live USB

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Puppy Linux, an example of an operating system for live USBs Puppy Linux Xenialpup 7.5 CE.jpg
Puppy Linux, an example of an operating system for live USBs
Ubuntu 8.04 running Firefox, OpenOffice.org and Nautilus Live USB ubuntu.png
Ubuntu 8.04 running Firefox, OpenOffice.org and Nautilus

A live USB is a portable USB-attached external data storage device containing a full operating system that can be booted from. The term is reminiscent of USB flash drives but may encompass an external hard disk drive or solid-state drive, though they may be referred to as "live HDD" and "live SSD" respectively. They are the evolutionary next step after live CDs, but with the added benefit of writable storage, allowing customizations to the booted operating system. Live USBs can be used in embedded systems for system administration, data recovery, or test driving, and can persistently save settings and install software packages on the USB device.

Contents

Many operating systems including Mac OS 9 , macOS , Windows XP Embedded and a large portion of Linux and BSD distributions can run from a USB flash drive, and Windows 8 Enterprise has a feature titled Windows To Go for a similar purpose.

Background

To repair a computer with booting issues, technicians often use lightweight operating systems on bootable media and a command-line interface. The development of the first live CDs with graphical user interface made it feasible for non-technicians to repair malfunctioning computers. Most Live CDs are Linux-based, and in addition to repairing computers, these would occasionally be used in their own right as operating systems.

Personal computers introduced USB booting in the early 2000s, with the Macintosh computers introducing the functionality in 1999 beginning with the Power Mac G4 with AGP graphics and the slot-loading iMac G3 models. [1] Intel-based Macs carried this functionality over with booting macOS from USB. [2] Specialized USB-based booting was proposed by IBM in 2004 with Reincarnating PCs with Portable SoulPads and Boot Linux from a FireWire device. [3] [4]

Benefits and limitations

A USB flash drive Sony Micro Vault Tiny 4 GB.jpg
A USB flash drive

Live USBs share many of the benefits and limitations of live CDs, and also incorporate their own.

Benefits

Limitations

Setup

Various applications exist to create live USBs; examples include Universal USB Installer, Rufus, Fedora Live USB Creator, and UNetbootin. There are also software applications available that can be used to create a Multiboot live USB; some examples include YUMI Multiboot Bootable USB Creator [10] and Ventoy. A few Linux distributions and live CDs have ready-made scripts which perform the steps below automatically. In addition, on Knoppix and Ubuntu extra applications can be installed, and a persistent file system can be used to store changes. A base install ranges between as little as 16 MiB (Tiny Core Linux) to a large DVD-sized install (4 gigabytes).

To set up a live USB system for commodity PC hardware, the following steps must be taken:

Knoppix live CDs have a utility that, on boot, allows users to declare their intent to write the operating system's file structures either temporarily, to a RAM disk, or permanently, on disk or flash media to preserve any added configurations and security updates. This can be easier than recreating the USB system but may be moot since many live USB tools are simple to use.

Full installation

One alternative to the live operating-system solution would be a full installation; that is, a traditional installation, but without swap partitions. This option has the advantage of being efficient for the software, as it eliminates the need for the device to retain – separate from the persistent file – the operating-system’s installer software. However, full installation is not without disadvantages; due to the additional write cycles that it requires, the life of the flash drive may be slightly reduced. To mitigate this, some live systems are designed to store changes in RAM until the user initiates a system powerdown, which triggers the actual writes to the device. The trade-off is greater risk of lost work, in the case of an abnormal abort. Beyond these, another factor to consider is that, if the transfer speed of the storage device is poor, then performance can be reduced to a rate more typical of legacy computers – even for machines with modern components. This issue can usually be overcome by installing to a USB hard drive, as they generally perform better than flash drives, regardless of the connector.

Microsoft Windows

Although many live USBs rely on booting an open-source operating system such as Linux, it is possible to create live USBs for Microsoft Windows by using Diskpart [11] or WinToUSB. [12]

See also

    Related Research Articles

    <span class="mw-page-title-main">Linux distribution</span> Operating system based on the Linux kernel

    A Linux distribution is an operating system made from a software collection that includes the Linux kernel and often a package management system. Linux users usually obtain their operating system by downloading one of the Linux distributions, which are available for a wide variety of systems ranging from embedded devices and personal computers to powerful supercomputers.

    <span class="mw-page-title-main">Boot sector</span> Sector of a persistent data storage device

    A boot sector is the sector of a persistent data storage device which contains machine code to be loaded into random-access memory (RAM) and then executed by a computer system's built-in firmware.

    <span class="mw-page-title-main">GNU GRUB</span> Boot loader package

    GNU GRUB is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system's partitions.

    A boot disk is a removable digital data storage medium from which a computer can load and run (boot) an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting certain standards.

    <span class="mw-page-title-main">Live CD</span> Complete, bootable computer installation that runs directly from a CD-ROM

    A live CD is a complete bootable computer installation including operating system which runs directly from a CD-ROM or similar storage device into a computer's memory, rather than loading from a hard disk drive. A live CD allows users to run an operating system for any purpose without installing it or making any changes to the computer's configuration. Live CDs can run on a computer without secondary storage, such as a hard disk drive, or with a corrupted hard disk drive or file system, allowing data recovery.

    An optical disc image is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system. ISO images contain the binary image of an optical media file system, including the data in its files in binary format, copied exactly as they were stored on the disc. The data inside the ISO image will be structured according to the file system that was used on the optical disc from which it was created.

    <span class="mw-page-title-main">USB flash drive</span> Data storage device

    A Flash drive is a data storage device that includes flash memory with an integrated USB interface. A typical USB drive is removable, rewritable, and smaller than an optical disc, and usually weighs less than 30 g (1 oz). Since first offered for sale in late 2000, the storage capacities of USB drives range from 8 to 256 gigabytes (GB), 512 GB and 1 terabyte (TB). As of 2023, 2 TB flash drives were the largest currently in production. Some allow up to 100,000 write/erase cycles, depending on the exact type of memory chip used, and are thought to physically last between 10 and 100 years under normal circumstances.

    <span class="mw-page-title-main">Multi-booting</span> Act of installing multiple operating systems on a single computer

    Multi-booting is the act of installing multiple operating systems on a single computer, and being able to choose which one to boot. The term dual-booting refers to the common configuration of specifically two operating systems. Multi-booting may require a custom boot loader.

    <span class="mw-page-title-main">UEFI</span> Operating system and firmware specification

    Unified Extensible Firmware Interface is a specification that defines the architecture of the platform firmware used for booting the computer hardware and its interface for interaction with the operating system. Examples of firmware that implement the specification are AMI Aptio, Phoenix SecureCore, TianoCore EDK II, InsydeH2O. UEFI replaces the BIOS which was present in the boot ROM of all personal computers that are IBM PC compatible, although it can provide backwards compatibility with the BIOS using CSM booting. Intel developed the original Extensible Firmware Interface (EFI) specification. Some of the EFI's practices and data formats mirror those of Microsoft Windows. In 2005, UEFI deprecated EFI 1.10.

    Puppy Linux is an operating system and family of light-weight Linux distributions that focus on ease of use and minimal memory footprint. The entire system can be run from random-access memory (RAM) with current versions generally taking up about 600 MB (64-bit), 300 MB (32-bit), allowing the boot medium to be removed after the operating system has started. Applications such as AbiWord, Gnumeric and MPlayer are included, along with a choice of lightweight web browsers and a utility for downloading other packages. The distribution was originally developed by Barry Kauler and other members of the community, until Kauler retired in 2013. The tool Woof can build a Puppy Linux distribution from the binary packages of other Linux distributions.

    In computing, data recovery is a process of retrieving deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media or files, when the data stored in them cannot be accessed in a usual way. The data is most often salvaged from storage media such as internal or external hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, magnetic tapes, CDs, DVDs, RAID subsystems, and other electronic devices. Recovery may be required due to physical damage to the storage devices or logical damage to the file system that prevents it from being mounted by the host operating system (OS).

    <span class="mw-page-title-main">Apple–Intel architecture</span> Unofficial name used for Macintosh models that use Intel x86 processors

    The Apple–Intel architecture, or Mactel, is an unofficial name used for Macintosh personal computers developed and manufactured by Apple Inc. that use Intel x86 processors, rather than the PowerPC and Motorola 68000 ("68k") series processors used in their predecessors or the ARM-based Apple silicon SoCs used in their successors. As Apple changed the architecture of its products, they changed the firmware from the Open Firmware used on PowerPC-based Macs to the Intel-designed Extensible Firmware Interface (EFI). With the change in processor architecture to x86, Macs gained the ability to boot into x86-native operating systems, while Intel VT-x brought near-native virtualization with macOS as the host OS.

    <span class="mw-page-title-main">Recovery disc</span> Media intended to restore the operating system

    The terms Recovery disc, Rescue Disk/Disc and Emergency Disk all refer to a capability to boot from an external device, possibly a thumb drive, that includes a self-running operating system: the ability to be a boot disk/Disc that runs independent of an internal hard drive that may be failing, or for some other reason is not the operating system to be run.

    <span class="mw-page-title-main">Boot Camp (software)</span> Built-in macOS software to natively install Microsoft Windows on a Mac.

    Boot Camp Assistant is a multi boot utility included with Apple Inc.'s macOS that assists users in installing Microsoft Windows operating systems on Intel-based Macintosh computers. The utility guides users through non-destructive disk partitioning of their hard disk drive or solid-state drive and installation of Windows device drivers for the Apple hardware. The utility also installs a Windows Control Panel applet for selecting the default boot operating system.

    <span class="mw-page-title-main">EFI system partition</span> Partition used by Unified Extensible Firmware Interface

    The EFIsystem partition or ESP is a partition on a data storage device that is used by computers that have the Unified Extensible Firmware Interface (UEFI). When a computer is booted, UEFI firmware loads files stored on the ESP to start operating systems and various utilities.

    <span class="mw-page-title-main">Target Disk Mode</span>

    Target Disk Mode is a boot mode unique to Macintosh computers.

    The Linux booting process involves multiple stages and is in many ways similar to the BSD and other Unix-style boot processes, from which it derives. Although the Linux booting process depend very much on the computer architecture, those architectures share similar stages and software components, including system startup, bootloader execution, loading and startup of a Linux kernel image, and execution of various startup scripts and daemons. Those are grouped into 4 steps: system startup, bootloader stage, kernel stage, and init process. When a Linux system is powered up or reset, its processor will execute a specific firmware/program for system initialization, such as Power-on self-test, invoking the reset vector to start a program at a known address in flash/ROM, then load the bootloader into RAM for later execution. In personal computer (PC), not only limited to Linux-distro PC, this firmware/program is called BIOS, which is stored in the mainboard. In embedded Linux system, this firmware/program is called boot ROM. After being loaded into RAM, bootloader will execute to load the second-stage bootloader. The second-stage bootloader will load the kernel image into memory, decompress and initialize it then pass control to this kernel image. Second-stage bootloader also performs several operation on the system such as system hardware check, mounting the root device, loading the necessary kernel modules,... Finally, the very first user-space process starts, and other high-level system initializations are performed.

    <span class="mw-page-title-main">Clonezilla</span> Drive cloning software

    Clonezilla is an open-source suite of disk cloning, disk imaging and system deployment utilities. Clonezilla Server Edition uses multicast technologies to deploy a single image file to a group of computers on a local area network. Clonezilla was designed by Steven Shiau and developed by the NCHC Free Software Labs in Taiwan.

    A USB image — is bootable image of Operating system (OS) or other software where the boot loader is located on a USB flash drive, or another USB device instead of conventional CD or DVD discs. The operating system loads from the USB device either to load it much like a Live CD that runs OS or any other software from the storage or installs OS itself. USB image runs off of the USB device the whole time. A USB image is easier to carry, can be stored more safely than a conventional CD or DVD. Drawbacks are that some older devices may not support USB booting and that the USB storage devices lifespan might be shortened.

    References

    1. "USB Info and Benefits of Dual-Channel USB". Apple (published February 20, 2012). September 16, 2003. Archived from the original on May 12, 2013. Retrieved September 25, 2016. Bootable USB drives: A storage device such as a SuperDisk, Zip disk, or other USB storage drive can be used to hold a valid system folder and used at startup.
    2. "Starting from an external USB storage device (Intel-based Macs)". Apple. March 22, 2016. Archived from the original on May 22, 2016. Retrieved September 25, 2016.
    3. Singer, Michael (August 15, 2005). "IBM brains capture a PC's soul". CNET. CBS Interactive. Archived from the original on September 27, 2016. Retrieved September 25, 2016.
    4. Honeyford, Martyn (July 15, 2004). "Boot Linux from a FireWire device". IBM DeveloperWorks . IBM. Archived from the original on January 17, 2007. Retrieved May 15, 2016.
    5. Trevor (May 6, 2010). "Boot from a USB Drive Even If Your BIOS Won't Let You". How-To Geek. Archived from the original on September 23, 2016. Retrieved September 25, 2016.
    6. "Plop Boot Manager". February 7, 2012. Archived from the original on February 8, 2012. Retrieved September 25, 2016.
    7. "Universal USB Installer - Bootable USB Software - UUI". PenDrive Linux. 2010-02-10. Retrieved February 17, 2024.
    8. knome (December 14, 2013). "MactelSupportTeam/EFI-Boot-Mactel". Ubuntu Community Help Wiki. Canonical Ltd. Archived from the original on March 4, 2016. Retrieved September 25, 2016.
    9. "XFCE minimum install HD". Linux Mint Forums. Archived from the original on September 27, 2016. Retrieved September 25, 2016. Live cd only write to the swap partition if your pc has one.
      If it doesn't it'll only use your RAM.
    10. "YUMI - Multiboot USB Creator | Easily Boot from USB Windows". Pendrive Linux. 13 March 2011. Archived from the original on 2017-10-23. Retrieved 2024-02-17.
    11. nnamuhcs. "Create a Bootable USB Flash Drive". docs.microsoft.com. Archived from the original on 2018-09-16. Retrieved 2021-09-15.
    12. Gordon, Whitson (21 April 2014). "How to Run a Portable Version of Windows from a USB Drive". Lifehacker. Gawker Media. Archived from the original on September 25, 2016. Retrieved September 25, 2016.