Data recovery from bad sectors can be done for fixed disks, external drives and USB devices. You could find OS built in tools, third party software apps and hardware apparatus for this purpose. Your first task is to diagnose the drive for the nature and extent of damage caused by the bad sectors. Then you will be able to determine the type of tool to be used to recover data from those affected areas. For that you need to be familiar with the root causes of bad sectors, their growth pattern and the way in which they affect the data stored. In this session you start off with an overview of bad sectors.
When the HDD or another storage media gets affected by bad sectors, the first steps you need to take is assessing their intensity and nature. We have a collection of professional and open source software tools for diagnosing and fixing most types of bad sectors. You can find reliable links to hardware tools with us for reliably repairing the bad sectors, when software tools are insufficient for performing the task.
Structure of hard disk drive
Physical structure of hard disk consists of a metallic shaft on which the cylinders are mounted. Each cylinder consists of tracks, sectors and clusters. Data is read and written with the help of an actuator arm. It has a head at the corner which is responsible for the I/O operations.
Sectors and Clusters: – Sector is the unit made of 512 bytes of data. It is the minimum storage unit in your HDD. When multiple sectors are joined together they form a block. A cluster is a structure meant for allocation of files and folders. Size of clusters determines the ease with which data is transacted within the HDD.
Tracks: – Tracks are circular in shape which uses cylinder head record made up of multiple sectors. Data access is done when the actuator starts moving within the inner and outer parts of the disk. This architecture makes it easy for the system to get access to multiple cylinders within the HDD layers.
Origin and spread of bad sectors
Bad sectors could start off with various forms of physical damage to the HDD. They may be initiated by electrical spikes, voltage or current fluctuations, damaged actuator head, high temperature within the HDD, PCI bus problems, regular wearing and other mechanical stresses.
Main problem with bad sectors is that they spread rapidly after getting initiated. You may not be able to notice them in the initial stage, but once they start spreading you could observe several symptoms in the various stages of bad sectors
Disk Failure symptoms
- Booting: – Computer booting slows down considerably. It takes a long time for the OS and startup applications get load completely.
- Applications: – You may not be able to run multiple applications simultaneously, especially when you are using Windows OS and try to run office and emailing programs.
- CHKDSK: – Disk checking process gets initiated automatically during OS startup.
- Noise: – The HDD starts generating cracking noise while you perform I/O operations. They may be light in the initial stages, but it won’t take longer for their intensity to multiply. Noise is generated by the actuator head as it moves over bad sectors, trying to read and write data.
Effective Diagnosis and Repair
You can use the built in hard disk utilities for scanning the bad sectors. Alternately you can also download and use hard disk scanning software apps from the internet. Once you have determined the intensity and nature of bad sectors, you need to fix them.
EaseUS: – EaseUS is one type of software which can be sued for fixing many types of bad sectors and data extraction. The system uses a wizard that runs in several steps. Version 10 released in 2016 is said one of the powerful editions of the software. Once you start the software you can simply select the drive that needs to be fixed for bad sectors. The system is capable of fixing bad sectors in the surface areas, interior sectors, partition table and boot sectors from multiple cylinders.
Before fixing the bad sectors, the software recovers data from the affected areas. This step is said to be highly needed as fixing of bad sectors can literally destroy the data stored in them. Data recovered from these sectors are written onto the good sectors.
YODOT: – YODOT is another software tool used for recovering data from bad sectors. You can download and install the software for windows, Linux, Android and other smart phones. It works for HDD, data cards, pen drives, SD cards, Flash cards and many other data storage devices effectively.
ICARE: – ICARE is a said to be highly preferred for Windows server systems. The tool run is 3 modes covering deleted files, deep scan mode and partition recovery. You need to run the deep scan utility of the software.
Hardware Tools for bad sectors
Dolphin Data Labs have released a hardware tool for detecting and fixing bad sectors from HDD, flash card, SD card and other storage media. It is a firmware type of repairing tool which probes deep into the drive, detects the bad sectors and fixes them.
- You need to ensure that complete data from the drive is backed up or recovered with the help of a reliable data recovery tool onto another media. It is because of the possible data deletion from bad sectors when the tool repairs them.
- Connect the HDD to the tool and run the built in firmware application. Once the system starts its operation, it tries to fix the damaged sectors without deleting the data. If it is not successful, it generates a warning signal before overwriting the data.
NOTE: – It is always better to protect your system drives from spikes and other electrical problems by installing UPS. Always buy branded hardware for storage purposes. When your HDD encounters problems with bad sectors, it is possible to recover data from most of them with software apps and hardware tools. It is better to mark the BAD sectors so that they are not accessed by the actuator arm during I/O operations.