A Digital Data Backup Philosophy
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Why and how to do data backups
Data backups are essential to have a certainty that the data is not
lost until it is required to be accessed later. A computer has
different hardware and software components that are in interplay with
each other and can have defects in their implementation that are
internal to one component or at the interaction between two or more
components. Also there exists the possibility of mistaken interaction
of the user with the computer system that leads to data loss. The
mitigations that together make data loss excedingly unlikely are
saving often, backing locally to two different devices, backing
somewhere offsite and testing the backups regularly.
Hardware and software failure
Components in the computer system are prone to failure. The first
reason is the complex and unreliable nature of the technology that
powers them. Hardware components that are to be sloted in a computer
have built in from their design the possibility of failure in their
normal operation parameters. By comparison software components are
worse when it comes to reliable operation. The corectness of their
functionality in unusual usage scenarios is often neglected in the
design phase and relegated to fixing bugs that are reported by end
users in their day to day usage of the suposedly finished product.
The second reason is the market realities that govern the computer
industry and that drive companies to cut corners. Competition and
greed makes companies try to reduce production costs to produce a
cheaper product by comparison to the competitors.
User's own mistakes
Temporary lack of attention can lead to data loss in the usage of a
computer system. For example one may try to copy one file from a
folder to another folder and by mistake overwrite an existing file
in the destination folder. There is also the possibility of having
a wrong mental model of the way the computer system actually works.
For example one may think that the system will do automatical backups
of data because some other system they used in the past did
automatical backups of data, but the new system may require the
manual operation of a user interface menu to do the backup.
Save often
One way to avoid data loss is to save the data to storage that
is meant to be permanent often. For example I save roughly every
time I end typing a sentence after I input the full stop mark.
This avoids the situation where I lose data if there is a power
loss that wipes the temporary storage area. All modern computer
systems have a temporary storage area. Also most software that
is manipulating data that needs to be saved to permanent storage
after being edited in doesn't save the data automatically but
keeps it in the temporary storage area. The existence of
temporary and permanent storage areas is by design and habit
because temporary storage is much faster and it doesn't degrade
in time under heavy usage. Therefore it is important to learn
how to save data in a computer system and the software programs
you use in that system and do it often.
Use a file snapshot system
All important computer operating systems have available what is
commonly called a snapshot system for files. The system litarally
makes copies of the files that are being edited by users or
modified automatically by software programs in a way that is
efficient technologically. The system usually has to be activated
to work. It will make copies at regular intervals that are spaced
out in time for saving your work to permanent storage and it is
useful if one may want to recover work that was drafted and saved
to permanent storage but overwritten afterwards by a later save
to permanent storage. Find out about the file snapshot system for
files for your personal computer system and use it.
Backup to two local devices and offsite
At a more spaced out interval I save my work to two different
local devices and offsite. The reason I backup to two devices
is that one of those devices may fail exactly when the main
device failed as well and therefore I still have one local
device that holds my data. Backing up offsite to a cloud
storage offering as well is important because of the
possibility of disasters. When a disaster happens you cannot
rely on any local device to maintain the data they were
holding. Therefore local storage is not enough to ensure the
permanency of your data.
Test backed up data at regular intervals
The way you can loose data on your main system is also the
same way data on your backup systems can be lost. But the
issue is problematical in the sense that you do not interact
with the backup system every day to notice that the data has
been actually lost. Therefore there needs to be a preferably
automatical way to check that the data is still in place.
You do not want to end up at some point in the future with a
situation where your last backup system works as intended
but the data it holds was written to it in a corrupted state
in the first place. Check the data on the backups to see that
it actually is there as intended to be.