There are three backup types:
Full backups typically back up the entire contents of a server, whether they’ve
changed or not.
incremental backup stores all files that have changed since the last Full,
Differential, or Incremental backup. The chief advantage of an incremental
backup is that it takes the least time to complete, and requires less storage
space. However, during a restore operation, you need to process each incremental
back for complete restoration. This could result in a lengthy restoration time
compared to Full and/or Differential backups.
differential backup contains all files that have changed since the last full
backup. The advantage of a differential backup is that it shortens the backup
and restore time compared to a full backup and incremental backup.
Tape Rotation Schedule:
The rotating backup tapes is
the easiest way to manage a tape backup scheme. Some of the rotations are,
Weekly Rotations are the
simplest one. A tape is assigned to each weekday and labeled with the name of
the day. There will be five tapes and each tapes are overwritten as the day of
the week comes again.
Monthly rotation will help in
restoring data for an entire month. Managing this type of backup scheme is more
complicated because more tapes must be kept in track.
Yearly backup can be build on
top of the monthly system. The tapes needed are 12, one for each month, labeled
with the names of the months.
is one of the most commonly used tape backup schemes. With this rotation backups are
taken daily, weekly, and montly. The
daily incremental backups are known as the Son, because the daily taps are reused after a
week. The last full backup of the week is known as the Father, because the
weekly tapes stay for a month and are reused during next month. The last
full backup of the month is known as the Grandfather. Grandfather tapes are the oldest and
are retained for a year before reusing them. Note that the G-F-S is a
hierarchical backup mechanism, and it can be used for backing up using CD media
as well, in the same way it is used for tape backup.
virus is a program that causes malicious change in your computer and makes
copies of it. Sophisticated viruses encrypt and hide themselves to thwart
A file virus attacks executable
application and system program files, such as those ending in .COM, .EXE and
.DLL. Most of these types of viruses replace some or all of the program code
with their own.
A macro is a command script that is used to automatically
perform operations without a user’s intervention. A Macro virus, for example,
may use the Visual
Basic macro-scripting language to perform malicious or mischievous functions in
data files created with MS Office products.
Boot sector viruses affect the master boot record (MBR) of a computer. MBR is track one, sector
one on your hard disk. Any computer,
at bootup, checks MBR to find a pointer for the operating system. A boot
sector virus will overwrite the boot sector, thereby making it look as if there
is no pointer to your operating system.
An anti-virus scan is the process in which an anti-virus program examines the
computer suspected of having a virus and eradicates any virus it finds. There
are two types of anti-virus scans:
on-demand scan searches a file, a directory, a drive, or an entire computer. An
on-access scan checks only file you are currently accessing. To maximize the
protection both should be used in combination.
One most frequently used
application for on-access scan is email access. When you are using, say
Thurnderbird (a Mozilla email client program) to access email, an on-demand
anti-virus program kicks-in, and scans incoming email One such program, free for
home use, is AVG Antivirus program. AVG is both an on-demand, and on-access