Physical Damage
A wide variety of failures can cause physical damage to storage media. CD-ROMs can have their metallic substrate or dye layer scratched off; hard disks can suffer any of several mechanical failures, such as head crashes and failed motors; tapes can simply break. Physical damage always causes at least some data loss, and in many cases the logical structures of the file system are damaged as well. Any logical damage must be dealt with before files can be salvaged from the failed media.
Most physical damage cannot be repaired by end users. For example, opening a hard disk drive in a normal environment can allow airborne dust to settle on the platter and become caught between the platter and the read/write head, causing new head crashes that further damage the platter and thus compromise the recovery process. Furthermore, end users generally do not have the hardware or technical expertise required to make these repairs. Consequently, data recovery companies are often employed to salvage important data.
Read more about this topic: Data Salvaging
Famous quotes containing the words physical and/or damage:
“Life on board a pleasure steamer violates every moral and physical condition of healthy life except fresh air.... It is a guzzling, lounging, gambling, dog’s life. The only alternative to excitement is irritability.”
—George Bernard Shaw (1856–1950)
“If every man possessed everything he wanted, and no one had the power to interfere with such possession; or if no man desired that which could damage his fellow-man, justice would have no part to play in the universe.”
—Thomas Henry Huxley (1825–95)