All computers contain unique private or business information. Therefore regular backup is essential thing,
which defend vital data against loss forever.
Choosing of proper backup device gives a guaranty
of valuable data recovery. Durability of backup device must enough
to keep backup archives during planned period of time.
There are long-term and short-term backup archives in common practice.
At now usb backup devices are very popular, because it is cheap and simple to use.
Usb flash device has tiny weight and extra portable. It often use for a transfer of custom data
from and to portable digital devices: photo and video camera, audio and video player, smartphone and laptop.
Capacity of usb flash device grows and price per gigabyte is decreased by every year.
Such usb device will be a best solution for backing up of mobile digital devices.
It can be a short-term backup storage for desktop computers too.
Solid technology of the device protect data from damage during shaking as in operate as in transporting.
But flash device is sensitive to electrical fields. Especially connection and disconnection of the device
to faulty or harmful equipment may damage keeping data of even the device. In most cases data recovery
is very hard and can be done by special software in service center. If flash device using as a main backup device,
you must use several devices for every day backing up to prevent loss of critical data.
Transfer speeds of usb flash devices are varying. Same capacity models from different manufacturers
have transfer speed several times faster than another. Declared speed is most optimistic
and real depends on size and amount of files, which transferring to device.
Amount of overwrite cycles is enough to make every day backup during several years.
This feature also depends on usb flash device model.
External usb hard disk is fast and cheap solution for huge data backup.
Speed can be a sensitive feature, because time frame for data backing up is always limited.
For example business data must be transferred to backup device overnight;
therefore only 5-10 hours are available for everyday execution.
Capacity of external usb hard disk allows keeping several backup archives.
But several devices must be used for security purpose, because backup data can be distorted
or erased by virus attack or intentional human action.
It is not as portable as flash device, because hard disk is fragile device.
Extra shaking can damage it during transporting. It does not mean what this device can be used in one building only.
But moving it to off-site location must be done carefully.
Hard disk has very large amount of overwrite cycles. There is no reason to estimate it,
because device will be replace by new one in conjunction with new extra capacity requirements.
1) Usb flash disk is the portable solution for small and medium size short-term backup archives;
2) External usb hard disk is optimal backup device for backing up of huge data.