Data recovery from deleted partition is performed with the help of repartitioning tools and data recovery software. First task in the process is to restore the partition since the software will not be able to read data from corrupt partition. This requires a scanning tool which can determine the file type, cluster size, location of cluster 0, and total number of sectors, size of index buffer and the total number of clusters in the disk drive. It can be performed with the help of open source software tools you find online. However if your disk is large in size (> 20 GB) with multiple file systems and partitions, the speed of data recovery may be slowed down and you may not be able to restore critical files from the disk.
When you opt for the services from a professional data recovery expert, he will be able to use an effective combination of hardware and software tools to restore all the deleted/ corrupt partitions in your disk drive and recover files to the last byte. In this regard you can avail our data recovery services comprising of enterprise level tools which support multiple disk and file formats. Our system actively supports SATA, PATA, SAS, IDE and all memory & flash card formats for mobile, smart, phone and tablet PCs.
Functional features of partition recovery
As you are aware file systems can be FAT, NTFS, HPFS, HFS, HFS+ etc. When a partition error occurs it may convert them into RAW format and make the data inaccessible. In such cases the system will show an error message regarding disk formatting. An experienced technician will always avoid formatting the drive before data has been recovered from it.
Logical partitions: – Your storage device has a primary partition which comes by default. In most of the systems it is called the c:\ drive. You might have created many logical partitions which may start from d:\ and extend further. Partitions can get corrupt or deleted due to hardware, OS and file system corruption. Before recovering the logical partition it is mandatory to remove the cause of partition deletion. For example if virus attack has distorted the partition, an antivirus tool will be used to eliminate them before trying to recover the partition. Professional level software tools will be able to detect the original partitions in the disk using a recursive search algorithm. Partition mapping scan is one such algorithm which works recursively through the partition tables of the disk and detects them. The procedure involves several simple steps for different file systems like NTFS, FAT and HFS etc.
Partition restore: – The technician will connect your failed storage device to the desktop PC and run the partition restore software. In most of the cases the connection will be done through USB ports. The software will show the physical drives from fixed and USB devices in GUI format. The system will also show logical drives within each physical drive. Normally it will show only the physical drive in case of partition failed storage device initially. Once the logical partitions are restored by the software utility, logical partitions also get displayed on the screen. But accessibility to data may still take time as the file system needs to be restored now.
File system restore: – The technician will now launch the software utility for restoring the file system. Recovery engine displays options for the nature of data loss. Generally the options will be
- Default setting: – This setting is used when you are not sure about the reason. It is the auto mode.
- File system damage: – You might have accidentally formatted the logical partitions or run partition deletion utility. In this case the system uses a combination of partition data recovery and file system restore algorithms.
- File system overwriting: – This happens when you install another OS into the same disk for multiple OS facility. The new OS could have accidentally overwritten the file system of existing OS. This sort of scenario is common when you install Windows and Linux or another OS in the same disk drive. Complete partition scan is run in that stage and overwritten file system is restored.
- File Deletion: – You may have deleted the files unintentionally. In this case the software utility will try to undelete the files by tracking their links with the NTFS, FAT, and HPFS, HFS or other allocation tables.
Once the technician makes the selection and clicks on the NEXT button, the system will start scanning the failed drive. Time taken for the scan depends on the nature and intensity of damages to the file system. In case of logical damages, the process will be relatively faster. In case of physical damages it may take a few hours for complete scanning. The system will display list of restored files from each logical drive in the failed disk. You may choose to recover only a few files or all the files. You will be provided with options for restoration onto a different drive (if you have connected another USB storage device) or the parent drive.
Physical damages to drive
When the scan is in progress you may get messages for bad sectors. If their intensity is more than 40%-50%, there is no point in trying to recover data through this method. In such case you need to halt this process and switch over to disk imaging. The technician will disconnect failed drive from the desktop PC and connect it to a hardware tool for imaging along with a clean target device. By using this tool he will be able to create a mirror image of the disk. This is said to be a better option for physically damaged disks.
Once the mirroring is complete, he will be able to run the data restore software on the mirrored disk. The process will be relatively faster as the new disk is free from physical damages and only logical errors need to be fixed. But the process of imaging itself may take many hours depending on the nature and intensity of physical damages.