| Data Loss Is Not A Small Thing
| |
| | the system or the data from these backup
|
| The impact of a data loss on a business
| |
| | copies in case of a data loss.
|
| can be visualized if you consider a
| |
| | While in theory, backup is a foolproof
|
| manufacturing operation with over a
| |
| | safeguard; in practice things are quite
|
| thousand employees, whose pay details are
| |
| | complex. First comes the organizational
|
| kept in the company’s computer
| |
| | aspect.
|
| system.
| |
| | - Taking backups after every change
|
| Imagine what could happen if these pay
| |
| | - Selecting the media to store the
|
| details become inaccessible owing to
| |
| | backup, having regard to the costs and
|
| system problems, operator errors or a
| |
| | recovery steps involved
|
| malicious virus attack. Reconstructing
| |
| | - Keeping track of what data is on what
|
| the details is not going to be a
| |
| | media and which are the latest ones
|
| short-term operation.
| |
| | - Auditing the backup procedures and
|
| Yet such reconstruction is unavoidable
| |
| | media to ensure that they are indeed
|
| not only to pay the employees correctly
| |
| | reliable
|
| but also to comply with regulatory
| |
| | Numerous options are available for
|
| requirements under employment and
| |
| | backup.
|
| taxation laws. The cost of such a
| |
| | - Media for storage could be magnetic
|
| reconstruction is going to be a major
| |
| | tapes (least expensive but slow
|
| expense item for the company, not to
| |
| | retrieval), hard disks (fast retrieval
|
| mention the disruption to business
| |
| | possible but was comparatively quite
|
| operations.
| |
| | expensive until recent times)
|
| On the other hand, if the company had
| |
| | - Data could be backed up fully, or
|
| taken proper actions to make recovery of
| |
| | incrementally, or continuously, with
|
| the lost data possible, the time,
| |
| | different cost and recovery implications
|
| business disruption and money costs would
| |
| | - The backed up data could be stored in a
|
| be insignificant compared to a complete
| |
| | way that enables immediate online access
|
| reconstruction from scratch.
| |
| | or in offsite vaults or disaster recovery
|
| How Data Gets Lost
| |
| | centers
|
| An awareness of the different ways data
| |
| | - Remote third party backup services
|
| could get lost should be the starting
| |
| | could be utilized getting the benefit of
|
| step in organizing your defenses. So we
| |
| | their expertise and facilities
|
| look at these first.
| |
| | The above options are actually only
|
| Data stored on a computer disk can be
| |
| | illustrative. There are more options and
|
| lost in several ways.
| |
| | sub-options available to suit different
|
| - User Action
| |
| | requirements. The availability of the
|
| - The computer user deletes a data file
| |
| | options and their different implications
|
| or computer program thinking that it is
| |
| | make selection of a backup policy a
|
| no more needed. It could later turn out
| |
| | complex exercise.
|
| that the deletion was premature.
| |
| | In practice, backup is mostly
|
| Accidents
| |
| | unsatisfactory in implementation and far
|
| - User deletes file or program, but not
| |
| | from adequately dependable.
|
| with full awareness of what he is doing.
| |
| | RAID: RAID through hardware or software
|
| For example, a blanket deletion of a
| |
| | implements redundant storage so that the
|
| large number of files could result in
| |
| | failure of a single disk does not result
|
| deleting some important files that the
| |
| | in data loss. RAID implementations have
|
| user would not have consciously deleted.
| |
| | different levels with different degrees
|
| - The files or programs were stored on
| |
| | of safeguards against data loss. RAID is
|
| removable storage media like floppy or
| |
| | not only a data loss safeguard; it is a
|
| compact disks or USB drives that were
| |
| | means for higher speed data access.
|
| misplaced and could not be found when
| |
| | Journaling: An apparently single write
|
| needed.
| |
| | operation actually involves several write
|
| - Errors made by network administrators
| |
| | operations. If some disturbance prevents
|
| and other administrative persons could
| |
| | one of these several operations being
|
| lead to the loss of important files or
| |
| | completed, the result would be invalid
|
| programs that their users might not have
| |
| | data. One remedy against such an event is
|
| deleted.
| |
| | maintaining a journal of all changes
|
| System or Infrastructure Problems
| |
| | before actually doing the write
|
| - Power could fail before the data could
| |
| | operation. If the write is not completed
|
| be saved to permanent memory and the user
| |
| | successfully, the operation can be
|
| might be unaware that it has not been
| |
| | replayed using the journal and completed
|
| saved.
| |
| | successfully.
|
| - Different kinds of hardware failure,
| |
| | Antivirus: Practically every computer
|
| such as contact between the read-write
| |
| | user would have by now become familiar
|
| head and the rotating disk platter in a
| |
| | with antivirus software that helps you
|
| hard disk drive (in normal operation,
| |
| | prevent virus attacks and even recover
|
| there is a minute cushion of air between
| |
| | any damage done by such attacks.
|
| the two), could lead to the data on the
| |
| | Firewalls: Firewalls act as a barrier
|
| disk becoming unreadable.
| |
| | between networks of different trust
|
| - Software crashes, as when an
| |
| | levels. The Internet is a network of no
|
| application or the operating system
| |
| | trust level while an internal network has
|
| suddenly gets stuck halfway through a
| |
| | a higher trust level. A firewall could
|
| work session, could result in the work
| |
| | control the data flow between the
|
| not being saved.
| |
| | networks by either allowing only
|
| - Data corruption as when the file system
| |
| | previously allowed network connections or
|
| or database gets corrupted and the data
| |
| | preventing specifically blocked
|
| in the files or database becomes
| |
| | connections. In practice, firewall
|
| unreadable, or when unintended changes
| |
| | implementation tends to be inefficient.
|
| during transmission or retrieval results
| |
| | User Education: Considering the fact that
|
| in erroneous data.
| |
| | user errors are a major factor for data
|
| External Factors
| |
| | loss, proper user education could go a
|
| - A natural disaster like an earthquake,
| |
| | long way in preventing data loss.
|
| flood or tornado destroys the equipment
| |
| | Data Recovery
|
| including the data storage media.
| |
| | Expert data recovery consultants could
|
| External Interference
| |
| | recover much of the “lost”
|
| - A worm or virus attack results in
| |
| | data not only because of their
|
| damage to data
| |
| | specialized training and experience but
|
| - A hacker intrudes into the system and
| |
| | also because they have the necessary
|
| erases/damages the data
| |
| | facilities, such as Class 100 Clean Rooms
|
| - A thief steals the physical media
| |
| | kept free of dust. Even minute specks of
|
| Of the above, hardware failure and human
| |
| | dust could make the thickly packed data
|
| errors reportedly account for 75% of the
| |
| | on disks unreadable.
|
| incidents. Data loss through natural
| |
| | These companies use techniques like
|
| disasters is rare. However, if that
| |
| | repairing the file system damage so that
|
| happens, there is no way to recover the
| |
| | the image on the disk could be deciphered
|
| data unless you had stored backups in a
| |
| | as meaningful data, replacing damaged
|
| physically separate location.
| |
| | PCBs or read-write heads with matching,
|
| Let us now look at ways to minimize data
| |
| | healthy ones, removing the platters from
|
| loss. You can only minimize it; absolute
| |
| | the damaged drive and installing them in
|
| protection even against minor losses is
| |
| | a healthy drive or a combination of these
|
| impracticable.
| |
| | measures.
|
| We also look at the possibilities of data
| |
| | It would be apparent that these are
|
| recovery if data does indeed get lost.
| |
| | procedures requiring high precision,
|
| Organizing Against Data Loss
| |
| | considerable expertise and specialized
|
| Backups: You copy all data and programs
| |
| | facilities. Attempting to do it in-house
|
| to a secondary media, preferably
| |
| | is only likely to make the data
|
| removable media that can be stored in a
| |
| | completely irrecoverable.
|
| separate location. You can then restore
| |
| |
|
