How to recover data on HDD for beginners

Your beginner’s guide to recovering data on HDD Andy Pham Share on Addiction Tech Group is quite detailed for those of you who are new to learning about how to recover deleted data on HDD. Here is the full post he shared:

When it comes to data recovery, users often think of professional centers with advanced lab systems. Any brother who knew me when I was still in Vietnam, my technical team provided technical support for a series of factories, data centers, banks… The number of computers was up to several thousand, so the cases of data loss. Does it have to be handled every few days? Each time you recruit a new KTV, throw the hard drive, some professional software, practice, delete, self-heal, feel the optimal solution. It takes about 3 days to be able to start talking on the internet, and after 1 week, the conversation begins to be very deep.

Data loss is often related to

1. Hardware: hard drive dropped, caught fire… the recovery requires labs with specialized equipment (this will not be discussed in the article below)
2. Software: virus bite, mistaken deletion, wrong format, wrong drive installed win… This in many cases can be restored perfectly if handled properly.

So how is it? right way and why is it possible? perfect restoreyou hear me a little lengthy.

Write/Write data

When writing/writing a file new file on the hard drive, after completing the file writing, the system will return to the FAT (File Allocation Table) version – temporarily called the file distribution diagram, and record information about that file such as file location, capacity ….

Read/Read data

When reading/reading files then the order is reversed, the system will access the FAT version first, based on the instructions of the FAT version to find the actual location of the file on the hard drive (not as the beginner thinks the system will go straight to the where that file is). At this point, you can imagine the FAT version as a “map” for the hard drive.

If the file is like a house, the entire hard drive is a city (for example, Hanoi), the FAT version is the map of Hanoi city, the whole system will operate this “map”.

Delete/Delete data

When deleting a file, the system deletes information about this file on the FAT “map”, not the actual file on the hard drive. The hard disk area in which the file exists will be considered wasteland (free). Next time there is a new file to create/write, just overwrite it. Therefore, if you are observant, you will see that the process of deleting files is very fast (sometimes several hundred files are only a few seconds), while the process of copying / writing that file can take up to a few hours. This is key point so that the data recovery software can get the data back.

So how do data recovery software work? The data recovery software will bypass the FAT “map” and directly scan the hard drive to find the actual file, the detailed scan to each block of the HDD to ensure the integrity of the file, so it usually a very long time (roughly a few hours). The software restores like a diligent cadastral officer, groping to every house in the city, taking actual measurements to restore the original map: this villa plot A1, A2, A3 belongs to Mr. Chung, chairman. , the adjacent lot B2, B3 belongs to Mr. Quyet… and so on until the city map is restored, the data is restored.

This example may not accurately reflect 100% of the actual operating system of the system, but through that you understand a key point: user-defined delete/format commands. do not delete files on the hard drive directly, the data is still there. So with a medium software + standard skills, you can restore data to perfection.

Common knowledge:

Format multiple times, can it be saved?

Have. Format (quick format) only differs from the delete command that it erases the entire FAT version (instead of just deleting some information on the FAT version like the delete command). The data remains intact on the hard drive. Formatting many times is no different from formatting once (deleting and deleting the FAT version). Although from the user’s perspective, multiple formats are much more terrible than one-time formats.

What factors affect data recovery on HDD?

As analyzed above, after deleting, file information will be removed on the FAT “map”, although the data is still there, but that land for the system is a wasteland, ready for use. any subsequent entries. Therefore, after deleting the file, but the user continues to use the computer, the recovery rate will decrease over time, or the recovered file will be incomplete (leading to failure to open). Another reason is that an inexperienced technician installs recovery software on the hard drive to be restored, which will write the title on the “land” with the files to be recovered.

Can an SSD be recovered when deleted by mistake?

No, specifically you can read here.

Which data recovery software should I use?

An average software + good skills ⇒ the ability to recover data on HDD can be close to 100%. So recovery skills are still the key point. You can refer to the best recovery software here:

1. The first is R-Studio, this guy is not the easiest guy to use, but absolutely the best guy. About 15 years ago, the client’s RAID server cluster crashed, it took about 2 weeks to order a replacement, but the customer is a manufacturer, I couldn’t wait that long, I used it to lift all the data. data out of the crashed server’s RAID cluster, then put out a normal Windows machine, sharing it for the entire factory for temporary use. At that point, each of it does. Later on, maybe some software has this feature. But it’s still number 1, it’s important to use it well in the most professional environment, recognized by the most demanding IT.
2. Monday is EaseUS Data Recovery powerful, easy to use, I already have a separate post about this guy
3. Tuesday is Stellar Data Recovery, GetDataBack… Now it is possible GetDataBack and some other software better known than R-Studio, but by the time R-Studio was 4-5 years old, GetDataBack Just starting to enter the data recovery software market. (2 This software is still given a copyright giveaway from time to time, you can watch to find the Key)

Advice for beginner KTV?

Recover data on HDD with software not difficult, as evidenced by a lot of ordinary users have been successful. But to achieve a 100% asymptotic success rate requires the KTV to operate only:

1. Ask the user to stop the operation immediately after mistakenly deleting
2. Make a backup of the mistakenly erased hard drive before restoring
3. Install the recovery software on a separate hard drive, preferably using a separate bootable USB
4. The recovered file must be copied to a separate hard drive (absolutely not copied to the wrongly deleted hard drive). Every small mistake will greatly reduce the possibility of recovery.

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