| Storage, more commonly, has been divided into | | | | emptying of recycle bin by mistake. Another |
| primary storage which holds data in memory (RAM or | | | | software error could be due to virus attack on the |
| random access memory) and other built-in devices | | | | system while downloading data from internet or |
| such as processors L1 and L2 cache; the other is the | | | | through copying of corrupt CDs. |
| secondary storage which holds data on hard disks, | | | | The physical errors leading to hard disk data loss |
| tapes and other devices requiring input/ output | | | | include first and foremost the hard disk crash. This is |
| operations. | | | | when the closely suspended read/ write head |
| Primary storage is much faster to access than | | | | becomes loose and crashes on the rapidly spinning |
| secondary storage because of the proximity of the | | | | platter. This platter is the recording surface on which |
| storage to the processor or because of the nature | | | | the data is stored. The head severely scratches the |
| of the storage devices. On the other hand, | | | | platter leading to data loss and damage. Other |
| secondary storage devices have larger capacities to | | | | hardware errors could be caused by natural |
| hold data than primary storage devices. | | | | calamities, electrical surge, impact trauma and so on. |
| Storage often is used to mean devices and data | | | | Losing data from the hard disk can be a serious |
| connected through input/ output operations, that is, | | | | setback to the user. There is hope, however, as the |
| hard disk and tape systems. So the term storage has | | | | data can still be recovered. Contrary to popular belief, |
| become synonymous with secondary storage in | | | | deleted files, though not available to the operating |
| common parlance. | | | | system of the computer, are still on the drive. Only |
| The options of secondary storage in terms of | | | | the names of the files are deleted from the table of |
| variety and pricing are much greater. The | | | | contents which results in operating system’s |
| development in digital technology is associated with | | | | failure in locating the files. This makes the system |
| development of new and better secondary storage | | | | mark the space occupied by these files on the drive |
| devices such as hard disk, floppy disks, CDs and tape | | | | as vacant. Vacant space can always be used to |
| drives. | | | | store or write new data leading to deletion or |
| A hard disk holds the maximum amount of data for a | | | | overwriting of the files. |
| PC. It stores and provides a relatively quick access to | | | | To prevent this from happening when a disk crashes |
| large amount of data on an electromagnetically | | | | and some data is lost, the user should immediately |
| charged surface or a set of surfaces. Present-day | | | | stop working on the computer immediately. He should |
| computers come with a hard disk that contains | | | | not run a programme, write mails or browse the net |
| several billion byte of storage. | | | | or even install DIY software. All these activities carry |
| Hard disk is really a set of stacked up disks just like | | | | the threat of creating new files and overwriting the |
| phonograph records which have data recorded on | | | | existing files. Any overwritten data will be lost |
| them in concentric circles (tracks) electromagnetically. | | | | forever. |
| A fixed head records (writes) and reads the | | | | In case of a hard drive crash also, no attempt should |
| information on these concentric tracks. Two heads, | | | | be made by the user to rectify the situation. He |
| one on each side of the disk, read and write the | | | | should immediately call a data recovery company |
| data as the disks spin with great speed. | | | | who will take the crashed hard disk and open it in a |
| Hard disks have huge storage capacities and they | | | | dust-free clean room. It needs expertise and |
| provide random access to the information stored on | | | | experience to retrieve any data from a crashed hard |
| them. They have long life spans and data can be | | | | disk and only professionals can do a good job of it. |
| written, created, shifted, modified and erased any | | | | They copy the recovered data on a new disk to be |
| number of times on them. This makes them an | | | | handed over to the user. |
| irreplaceable storage device. | | | | To prevent any critical situation like the one |
| Hard disks like all other storage devices can lose data | | | | mentioned above, one should have an adequate and |
| due to various reasons. These could be software | | | | timely updated backup of all crucial data. A properly |
| errors often triggered by the users themselves. | | | | stored backup will serve you well in times of need. |
| These include an accidental deletion of a file and | | | | |