Twenty ways to lose your data

I first encountered the loss of data when I lost my collection of carefully edited translations of my favorite book during the banal OS reinstallation. It was a long time ago, but the memories of hours of painstaking work, spent on bringing to mind several million characters of the text, still haunt me. At that time, there were no different cloud technologies like dropbox, so the loss was almost irreplaceable. Of course, not everything and not always so tragic - if the media itself is still there, the lost data can be recovered. Eh, I would know where you fall ...

Therefore, I decided that it would be more correct to devote my first post on the blog of a data recovery company to how this data is most often lost. So, your attention is the top 20 reasons why users usually remain without their precious information . Even if you are a guru of system administration, for example, it will not be superfluous to refresh the basics - to spread straws.

1. Neglecting backups

Data backup should be performed regularly, as well as - without fail before any manipulations with the system. At the same time, even experienced administrators make errors, saving the data to the same physical disk or raid array, or to another medium that is in the same place (in one system block 2 hard drives), without checking the backup archives (sometimes the archives are damaged, unsuitable for deployment). This will help avoid immediately more than half of the causes of data loss listed in this article.
')

2. Errors when using utilities

Attempting to recover corrupted or lost data using the software designed for this is not a bad idea. However, the use of such software is possible only under the condition that the media itself is healthy. Otherwise, you can only make it worse or lose data forever. Disastrous uses of utilities also include:

1. run on a working disk for testing disk
2. attempts to expand or merge logical partitions, convert file system
3. installation of software during data recovery after reinstalling the system on the same media; saving scan results to the same disk.

3. Neglect of fault signals

If the disk clicks or the system freezes / drops into the blue screen, then most likely it says goodbye to you in this way - it is better to transfer all data from it immediately, if you have time.

4. Sudden hang of the operating system

Previously, it was the scourge of God, now the programs themselves after a system failure restore the last saved version of the document. Windows, Mac OS, Linux - any axis can “grunt” at some moment and lose unsaved data. In this case, user data, files on the disk, as a rule, remain intact.

5. The actions of intruders

Attacking hackers is not the most common way to lose your data - not everyone threatens: first you need, nevertheless, to interest hackers. The most frequent case of such an attack is hacking into the accountant’s computer with a bank client, transferring all the money from the firm’s accounts, and then erasing or encrypting the media.

6. Viruses

Viruses can either start deleting your files one by one, or simply destroy the hard disk file system. The list of tips to avoid this situation is quite clear:

• Do not open unfamiliar links, even sent by friends.
• Carefully check the address from which the mail comes containing links
• Use antivirus and firewalls
• Create a user on the computer without administrator rights and work under it; if you need to install something, just log in
• Most viruses on porn sites and sites offering unlicensed software and media files
• Use alternative browsers, most viruses are designed for the most popular Internet browsers.

7. “Random” formatting

This happens when you start formatting, making a mistake with the disk. When the file system is damaged on the disk (mostly FAT 32) and the OS offers to format the device when the recovery partition is started on the laptop (it turns out that the system is reinstalled, the data is overwritten). After that - if you do not use the disk, but immediately contact a specialist, you can still restore the data.

8. Physical damage

A hard drive dies for various reasons. You can drop it, pour something, overheat, freeze or come up with a more ingenious way to destroy it. Here are some of the most common:

1. Drowning laptop in bath or sea
2. Pouring drinks
3. External drive dropped by hooking on the wire
4. Washing in a typewriter or cell phone
5. Overheating disk in a cheap case.
6. a flash drive sticking out - it will usually be caught and broken
7. overheating of covered external drives due to prolonged load
8. Anyway, only a specialist will be able to recover information from a damaged carrier, since it is practically impossible to restore the mechanics of the disc at home. The first to fail is a block of magnetic heads.

9. Damage to the read head of the hard disk.

The distance between the reading head and the disk itself is microscopic, maintained exclusively by the oncoming airflow. Therefore, the slightest speck of dust or a grain of sand that gets inside, destroys the disk. That is why you do not need to disassemble the disk yourself and try to fix it: experts disassemble it and assemble it in a special clean room or laminar box to prevent dust particles from entering the device, where all manipulations with the hard disk are carried out in dust-free space. Moreover, other conditions must be observed: preliminary cleaning of the external surfaces of the disk, so that dust and dirt from the body do not get inside after opening, antistatic coating, special clothes, so that skin particles, hair of the specialist’s clothes also do not get inside.

10. Hard disk sector failure

If the data is found in a bad cluster (sector) of the disk, it may be lost. Using disk markup, failed clusters can be truncated. This process of hiding bads (faulty clusters) is called sector reassignment, during the execution of which all data on the disk is irretrievably destroyed, since the entire surface of the plates is overwritten. As a rule, the emergence of bad blocks occurs over time with each hard drive to one degree or another as the disc mechanics wear out, overheat, i.e. These are the first signs of his imminent failure.

11. Duplicate SMART error messages

This is not a reason, it is an important sign: if you ignore it, you can lose data. Therefore, if such a message pops up regularly when the computer starts up, it is better to backup files, and for the hard disk, it is recommended that the “SMART” (Self-Monitoring, Analysis and Reporting Technology) test, which is recorded on the hard disk itself, is recommended.

12. Power failure

This is one of the common causes of data loss: if you turn off abruptly, the hard disk heads do not have time to park, which causes scratches or damage to the disk - as a result, unsaved files are lost, and those that were previously saved can be damaged. It is not uncommon that the entire computer fails with a sudden increase in the voltage in the power supply network: iron usually burns out during power surges — the hard disk electronics, the raid controller of the array, the controller of the flash drive. You can use UPS to prevent data loss in this way.

13. Damage to the hard drive utility

The firmware stored on the hard disk itself handles various tasks of the device. If it is damaged, the operating system cannot see or start working with the disk. It can be repaired, but expensive. And it is difficult to foresee. Therefore, against this scrap there is no other method, except for the good old backup. Absolutely reliable hard drives have not yet been invented, From what is on sale, we can recommend top models of hard drives Westen Digital Caviar Black RE4 and Hitachi. Among the drives for notebooks of 2.5 ”format, it is generally impossible to single out more or less reliable models.

14. Force Majeure

Among the most common for the central region of Russia and Moscow, force majeure data loss is the breakthrough of water pipes (or breakthrough of the heating battery, which is important in winter), fire, air conditioner malfunction in the server room. Often bring drowned while on vacation at sea laptops.

15. Long use flash drive

A flash drive is not a particularly reliable carrier and is designed for specific write / read cycles. Therefore, it is not recommended to constantly work on it or store your files. Very often, for example, accountants are constantly working "on a flash drive" at work and at home. Sooner or later the flash drive, having exhausted the recording cycles, will fail. By the way, new flash drives have a much smaller resource due to greater recording density.

16. Improper device removal

It is better to remove the memory cards when the device is turned off, and the flash drive must be “stopped” before removing. Of course, if this is not observed regularly, you can spend some time and not notice that something is happening. However, if data caching, the so-called delayed write, is enabled in the operating system, files are not written to the USB flash drive immediately. In case of unsafe extraction, you can pull out the flash drive while recording and lose data. In addition to the file system failure, the probability of a controller failure is also high.

17. Static electricity

Although flash drives and memory cards were originally planned as sufficiently mobile storage media, any manipulation with them can lead to data corruption. Static electricity can give discharge up to 3000 volts, and in order to spoil the electronics and damage the data, 12V is enough. And although flash drives are reliably protected with plastic, this option of data loss can also occur - so you can not touch your fingers with the contacts of memory cards, ssd disks. For example, in CF (Compact Flash) memory cards you can thus accidentally damage the thin contacts on the camera. And it is advisable to transfer photos from a camera to a computer via usb without removing the card itself.

18. Human factor

Of course, this definition fits into many of the situations described above, but still the passion for self-solving problems is sometimes not entirely appropriate. Independent attempts to recover deleted files almost always lead to damage to the magnetic plates, the head unit, pollution, the rise in the cost of information recovery, sometimes to the impossibility of removing the data in principle. However, since this cause of data loss is one of the most common, there is a special software that will recover your data. Perhaps the best advice that can be given here - turn off the computer, and consult a specialist. If, nevertheless, decide to use special utilities, then restore the data to another medium or, at least, a partition - otherwise the data can be lost altogether.

19. Intentional destruction

This happens if the file is deliberately deleted, cleaned the basket, or immediately shift-delete, and then change your mind and want it back. There are special utilities for recovering such files. The main thing in this situation is to prevent overwriting and not using the device. Although, of course, if you really need the information, it is better to entrust the restoration to professionals, especially since this is not the most expensive case of data recovery and you can restore them almost guaranteed.

20. Close an unsaved file

Close the file without saving - the action is very thoughtful, at first glance, because at least you need to confirm your intention. However, this also often happens. As a rule, the file can be immediately pulled out of the temp folder by hand.

And finally, a few tips that can help you not to lose your data forever:

1. Lost your data? - Turn off the computer!
2. Never open the hard drive.
3. Never defragment or scan a disk for errors after a crash.
4. Do not play with the settings of the hard disk partitions, do not try to split the hard disk, on which the system is, into several
5. Do not seek help from amateur friends and dubious firms.
6. Do not try to “revive” a failed hard drive.

In which case, you and your data will save:

• Backup
• Data Recovery Utilities
• Careful handling of the drive
• Data Recovery Specialists

PS This is the first post in the Storelab company blog on Habrahabr. We will talk about different methods of data destruction and recovery, features of software and hardware and methods of protecting against data loss in our next publications.