Boot image
Encyclopedia
A boot image is a type of disk image
(a computer file containing the complete contents and structure of a Computer storage media). When it is transferred onto a boot device it allows the associated hardware to boot
.
This usually includes the operating system, utilities and diagnostics, as well as boot and data recovery information. It also includes those "applications" used organization-wide. A specialized image for a particular type of user or department is called typically a departmental boot image
. Building such an image can take days or weeks, and involve complex decisions about licensing and permissions - including which passwords to store in the boot image and which to require users to type in - and requires experts in software integration to do.
However, once built, the boot image can be simply copied onto devices, patched within reasonable limits, and remains disposable in case of any problems (viruses
in particular). This is possible because:
Unlike other hard drive images (which may contain any data, et al.), pure boot images contain no mission-critical data. By definition a pure boot image contains no data that cannot be reproduced from configurations or off-the-shelf executables. In particular end-user data is not part of a boot image, although some operating systems require that a copy of user preferences or
configuration files be kept within the boot image itself, e.g. Microsoft Windows
registry
. Utilities like Norton Ghost keep a backup copy of the boot image, for quick re-imaging (often called re-installation) in case of problems, to avoid diagnosing specific problems with the image itself.
By keeping the boot image entirely separate and disposable, and mandating boot image control
, organizations seek to keep their total cost of operations (including its total cost of ownership
component) low. Often such organizations look at uptime as a service.
One goal of boot image control is to minimize the number of boot images used by an organization to reduce support costs. It includes at least:
Many organizations use thin clients for applications which require high security, involve unreliable users or repurpose older machines for continued use:
A cascading strategy involves re-imaging older, off-spec machines to thin client boot images so that they may continue in use for some less demanding or more access-controlled applications.
Disk image
A disk image is a single file or storage device containing the complete contents and structure representing a data storage medium or device, such as a hard drive, tape drive, floppy disk, CD/DVD/BD, or USB flash drive, although an image of an optical disc may be referred to as an optical disc image...
(a computer file containing the complete contents and structure of a Computer storage media). When it is transferred onto a boot device it allows the associated hardware to boot
Booting
In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the...
.
This usually includes the operating system, utilities and diagnostics, as well as boot and data recovery information. It also includes those "applications" used organization-wide. A specialized image for a particular type of user or department is called typically a departmental boot image
Departmental boot image
A departmental boot image is a boot image for any computer that has been enhanced by adding some applications and passwords specific to a task or group or department in an organization...
. Building such an image can take days or weeks, and involve complex decisions about licensing and permissions - including which passwords to store in the boot image and which to require users to type in - and requires experts in software integration to do.
However, once built, the boot image can be simply copied onto devices, patched within reasonable limits, and remains disposable in case of any problems (viruses
Computer virus
A computer virus is a computer program that can replicate itself and spread from one computer to another. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability...
in particular). This is possible because:
Unlike other hard drive images (which may contain any data, et al.), pure boot images contain no mission-critical data. By definition a pure boot image contains no data that cannot be reproduced from configurations or off-the-shelf executables. In particular end-user data is not part of a boot image, although some operating systems require that a copy of user preferences or
configuration files be kept within the boot image itself, e.g. Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
registry
Windows registry
The Windows Registry is a hierarchical database that stores configuration settings and options on Microsoft Windows operating systems. It contains settings for low-level operating system components as well as the applications running on the platform: the kernel, device drivers, services, SAM, user...
. Utilities like Norton Ghost keep a backup copy of the boot image, for quick re-imaging (often called re-installation) in case of problems, to avoid diagnosing specific problems with the image itself.
By keeping the boot image entirely separate and disposable, and mandating boot image control
Boot image control
A boot image control strategy is a common way to reduce total cost of ownership in organizations with large numbers of similar computers being used by users with common needs, e.g. a large corporation or government agency...
, organizations seek to keep their total cost of operations (including its total cost of ownership
Total cost of ownership
Total cost of ownership is a financial estimate whose purpose is to help consumers and enterprise managers determine direct and indirect costs of a product or system...
component) low. Often such organizations look at uptime as a service.
One goal of boot image control is to minimize the number of boot images used by an organization to reduce support costs. It includes at least:
- Specifying the machine hardware to minimize unneeded machine diversity and minimize the resultant number of boot images.
- Upgrading new machine specifications at low additional cost ensures that they will remain useful long past their normal life. Extending the life of desktop machines will reduce the incursion of off-spec machines later in the life-cycle, improving standardization, reducing support costs, minimizing e-waste.
- Organizing the network so that boot images can be efficiently supported, independent of data. Data must not be dependent on boot devices. Use networks to store data on secure servers.
- hardware acceptance testing on each new machine confirms that it is fit for use in a standardized boot image environment.
- Boot image installation to ensure that only supportable standardized boot images are used.
- TroubleshootingTroubleshootingTroubleshooting is a form of problem solving, often applied to repair failed products or processes. It is a logical, systematic search for the source of a problem so that it can be solved, and so the product or process can be made operational again. Troubleshooting is needed to develop and...
and help desk functions employ standardized tests to identify the source of problems: boot, software, or hardware. - Desktop system recovery tools and procedures for failed desktop units. These would use backup copies of a boot image created with utilities such as Norton Ghost. In a large organization with many compatible machines, rapid recovery by replacing with a backup boot image may only take a few minutes, with considerable cost savings.
- Data backup and recovery procedures ensure data is stored in the right place so that it can be recovered promptly in crisis situations.
- Installing services for the disabledServices for the disabledServices and supports for people with disabilities are those government or other institutional services and supports specifically provided to enable people who have disabilities to fully participate in society and community life...
with a single boot image in a manner that is ubiquitous and cost effective, meeting the needs of all staff regardless of disability, with available technology services. - Telework and secure off-site system access procedures.
- Facilitating worker transfer by changing boots or authorizations instead of moving machines.
- Using thin clientThin clientA thin client is a computer or a computer program which depends heavily on some other computer to fulfill its traditional computational roles. This stands in contrast to the traditional fat client, a computer designed to take on these roles by itself...
s for off-spec machines to eliminate the need for special boot images.
Many organizations use thin clients for applications which require high security, involve unreliable users or repurpose older machines for continued use:
A cascading strategy involves re-imaging older, off-spec machines to thin client boot images so that they may continue in use for some less demanding or more access-controlled applications.