Standards for Technology in Automotive Retail

 
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Chapter 17. Backups

Table of Contents

17.1. Overview
17.1.1. Backup Methods
17.1.2. What and When to Backup
17.1.3. Backup Media & Services

17.1. Overview

The practice of backing up data on a regular and timely basis using a reliable medium is critical to the success of a dealership. A loss of data can be costly not just in terms of money, but in terms of time, resources, and critical data that can in some cases be the backbone of a business. Any business working with data must have a backup procedure in place at all times.

The key to implementing an effective backup procedure that meets the dealership’s needs is to first understand the key components of a backup:

  • The type of backup

  • The frequency of the backup

  • The type of data and how much of that data to backup

  • The type of backup medium to use

17.1.1. Backup Methods

There are four backup methods that can be performed:

Full Backups

A full backup, the most comprehensive of the four backup types, contains the entire contents of a disk, including files and folders that have been selected for backup regardless of when they were last modified. Given that it is a full backup of all data, the time to perform the backup can be time consuming and requires adequate storage space. However, given the improvements in backup media these obstacles can be easily overcome. Although the full backup is more time consuming, it does however lead to speedier data restores.

Given the time it takes to perform a full backup, this backup method is typically relegated to weekly or monthly, and supplemented with daily differential backups.

It is considered a best practice to perform a full backup before any major system changes are performed.

Advantages

  • The full backup is the most comprehensive backup method.

  • The restore process is significantly faster than with other methods and will provide a more efficient and complete restore.

Disadvantages

  • While it is the fastest method to restore, conversely it is the slowest method for backing up.

  • The full backup method requires significantly more storage space than other methods of backup due to the amount of data being backed up.

[Backup4All2009]

Incremental Backups

An incremental backup contains only the files that have been modified since a previous backup. In the case of incremental backups, multiple backups are kept. There is an original backup of data that is stored, with all subsequent backups containing only information that has changed since the previous incremental backup. Due to incremental backups only containing data that has been modified, the method is more efficient both in time and storage requirements. If there is no change in the source data then there is no additional storage space being utilized and the backup is faster.

The draw back to the incremental backup can be found in its name. It is only an increment or increments of the full backup. Therefore, to perform a restore of the data requires the most current full backup in addition to all of the incremental backups performed since the that most current full backup was taken. This requires more restore time.

Advantages

  • With incremental backups only containing data that has changed, this method is extremely time and space efficient when it comes to performing a backup.

Disadvantages

  • While it may be more time efficient when performing a backup, it is considered one of the slower methods for restore.

[Backup4All2009]

[Wikipedia2009]

Differential Backups

A differential backup contains all of the files that have been modified since the last full backup was performed. This is not to be confused with an incremental backup which contains modifications since the last incremental backup was performed not the last full backup. Unlike an incremental backup, a differential is not as time and storage efficient requiring more time to backup and more storage space. In contrast, the differential method is quicker to restore than that of the incremental method.

When compared to a full backup, a differential backup will require less storage space but a longer restore time.

Advantages

  • Differential backups provide a quicker restore than that of incremental backups.

  • Differentials require less storage space and provider quicker backups than full backups.

Disadvantages

  • While differential backups provide a quicker restore than that of incremental backups, the opposite is true when backing up.

  • Similarly, while differential backups provide quicker backups than full backups, the opposite is true when restoring.

  • Storage space requirements for differential backups are higher than that of incremental backups but less than that of full backups.

[Backup4all2009]

Mirror Backups

While the full backup method is the most comprehensive, the mirror backup method is the fastest. A mirror backup is an exact replication of selected files and folders.

The mirror backup method is similar to the full backup method with two exceptions:

  1. Mirror backups do not compress files into an archive. Instead they are keep separate and "mirror" the original backup source files and file structure.

  2. Mirror backup files are not password protected.

These two exceptions are what make mirror backups the fastest backup method, however there are also draw backs to the method. The mirror backup method requires a large amount of storage space and version tracking of files is not possible.

Advantages

  • Mirror backups are considered the fastest backup method.

  • Because the backup is an exact mirror of the original source and not compressed, navigation of and access to files and folders is easier.

Disadvantages

  • Unlike full backups, files and folders are not compressed requiring larger amounts of storage space.

  • Files and folders are not versioned nor password protected.

17.1.2. What and When to Backup

How often data is backed up depends largely on how frequently the data is changed and the relative importance of the data. Data that is critical and that changes frequently should be backed up more frequently. For example, critical data that is changed on a daily basis should be backed up nightly . Data that is less critical and changes less frequently can be backed up on a weekly basis.

Regardless of the frequency at which a backup is performed, thought should be given to the scheduling of the backups relative to system usage. Optimal backup times would be when system usage is at its lowest, ideally during off peak hours.

As with frequency, the type of data chosen for backup depends on the importance of the data. Data that is critical, sensitive in nature and irreplacable would need to be backed up.

[MicrosoftTechNet2009]

Backing Up Software

In addition to backing up important data, it is also important to have backup copies of original software applications. When a system is being restored from scratch, all the original software applications must be reinstalled. If the original software media is available, it can be used for the restore. However, in the case of a disaster the original software media may have been destroyed. Therefore, it is critical to have a copy of the installation media on a cd or dvd and stored at an offsite location. Another software backup option is to keep a soft copy of the original software installation files backed up along with the other data that is being periodically backed up. With either option, it is important to maintain a copy of the original product license key. This information will be required upon installation.

One important component that should always be backed up is a system's operating system or "OS". Not only are OS backups vital in complete restores of downed systems from disasters, virsuses, etc., but they can also be useful when systems experience increasing amounts of performance degradation.

17.1.3. Backup Media & Services

When it comes to the media to be used in the backup of data, there are several different options available.

Magnetic Tape

Magnetic tape and tape drives, the device uses for performing the backup to the magnetic tape, is one of the oldest forms of data storage. Magnetic tape is typically packaged in cartridges and cassettes. It is capable of holding larges amounts of data and is less expensive then other backup media such as cds and dvds. Given the amount of available storage space on magnetic tape, it is typically used as a high capacity medium for large computer systems.

Once backups are made to magnetic tapes, the tapes are typically stored off site to guard against loss in the case of a disaster.

[Wikipedia2009]

Disc Imaging

A disk image is a software copy of a physical disk. It saves the entire data from the disk, including the file structure and all files and folders from the disk, in a single file. Because disk images are exact copies, or "clones," of original disks, they can be used to duplicate disks or serve as full backups in case a system restore must be done.*

Some companies use these images to restore information after a system crash while others use them as a maintenance tool. Some of the common uses for disc imaging are:

  • Protection of files and data

  • Producing working backups to manage the most common types of storage issues (e.g., mistakenly deleted files)

  • For use in Disaster Recovery testing and implementation

  • Easy testing of software configurations with virtual images

  • To ease system administration tasks

  • Backing up workstations for restoration or maintenance cleaning

[TechTerms2009]

On-site Hard Drive or Server

An on-site server or "backup server" as it is frequently referred to, is a computer used on the premises within the existing network to store copies from individual as well as other server machines. This machine is typically dedicated to storage only.

[PCMAG2009]

DVD

A DVD is a disc that is used for onsite backups, similar to magnetic tape and tape drives. The information is written to the DVD and is then stored either on or off site.

USB Drive

A USB drive, also known as a flash drive or keychain drive, is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a key chain. Storage capicity for a USB device typically ranges from 512mbs to 2gbs, although storage capacities continue to increase over time.

[SearchStorage2009]

Remote or "Off-Site" Server

Similar to the on-site server, the off-site server is used primarily for backing up data. However, this machine(s) is housed remotely in a separate location from the source of the data. The machine(s) is typically connected to the dealer's network with backups being run in an automated fashion.

Cloud-based Storage

Cloud-based storage, a still evolving storage service, provides both straight forward online storage approaches to full scale archive solutions. An Internet-based backup method, data identified for backup is sent via the web to a set of servers maintained by an outside provider specializing in cloud storage.

[SearchStorageChannel2009]

Risks

The following table weighs the risks factors to be considered when selecting a backup media.

Table 17.1. Backup Media Risk Factors

RisksTape DrivesIn-place Hard Drives DVDDVDOff-site ServerUSB DriveCloud
Hardware FailureHighHighHighHighHighMedium
Software FailureHighHighMediumHighMediumMedium
File System CorruptionHighMediumMediumHighHighHigh
Accidental DeletionHighHighLowHighHighHigh
VirusesMediumHighMediumHighHighHigh
TheftHighLowHighMediumHighMedium
SabotageHighLowHighHighHighMedium


Cost and Lifecycle

In addition to risk factors, cost and lifecycle must also be considered when selecting a backup media. The following is a list of considerations that should be taken into account:

  • Initial Cost - The amount it will cost to setup the initial backup process.

  • Ongoing Cost - This includes maintenance and purchase of media products such as additional tapes, DVDs or hard drives.

  • Scalability - The ability to expand the scale of the service to allow for more backups.

  • Automation - How easy is it to configure the backup service to run without a user having to start the process.

  • Convenience - How easy is it to retrieve or export the data or backup information.

  • Performance - What is the speed of the device or service.

  • Auditable - Can the information be accessed easily to perform internal audits of the backups.

The table below offers a rating for each consideration based on each backup media type.

Table 17.2. Backup Media Cost and Lifecycle

ConsiderationsTape DrivesIn-place Hard Drives DVDDVDOff-site ServerUSB DriveCloud
Initial CostMediumMediumLow/MedMed/HighLow/MedMedium
Ongoing CostMediumLowMediumMed/HighLowMedium
ScalabilityHighLowMediumHighLowHigh
AutomationLowHighLowHighLowHigh
ConvenienceLow/HighHighLow/HighMediumLow /MedHigh
AccessibilityLow/MedMediumLow /MedMediumLow/ MedMedium
PerformanceLow/MedMediumMed/HighMed/HighMediumMed/High
AuditabilityLow/MedMediumLow/MedMedLow/MedMedium