RecoverE2 is a software for data recovery and undeletion in ext2 file system. Aim of this project is to recover accidentally deleted files from ext2 file system. When a file is deleted from a computer it is not deleted immediately , instead OS marks the blocks, inode and directory entries associated with the file as unallocated. So if the blocks remain unallocated to newly created files we can recover it. The main features include versatile recovery filter that helps recover required files only and also facility to write the name and the associated inode of each file that is deleted to a log file.
Despite technological advances in the reliability of magnetic storage media, the incidence of data loss continue to rise.Data loss refers to unforeseen loss of data or information. An occurrence of data loss can be called a data loss event and there are several possible root causes. Data loss must be distinguished from data unavailability,such as may arise from a network outage. Although the two have substantially similar effects data availability is temporary while data loss is permanent. Backups and recovery schemes are developed to restore lost data. Data loss can be prevented by keeping regular data backups.
What is data recovery?
Data recovery is the process of salvaging data from damaged,failed,corrupted or inaccessible secondary storage media when it cannot be accessed normally.The two common techniques used to recover data from logical damage are consistency checking and data carving. While most logical damage can be either repaired or worked around using these two techniques,data recovery software
Typical causes of loss include
- Electromechanical Failure
- Natural Disaster
- Computer Virus
- Data Corruption
- Computer Crime
- Human Error
Uses of data recovery
- Law enforcement
- Locate illegal data
- Restore deleted/overwritten information.
- Average User
- Important lost files
- Keep your private information private
- Prosecute criminals based on discovered data
SECOND EXTENDED FILE SYSTEM
The Second Extended File system was devised (by Rémy Card) as an extensible and powerful file system for Linux. It is also the most successful file system so far in the Linux community and is the basis for all of the currently shipping Linux distributions.
- Optional block size at creation of an ext2 file system.
- Support immutable and append only files.
- Good implementation and file updating strategy.
- Support for good automatic consistency checks on the file system status at boot time.
- File system partition disk blocks in to groups.
- Fast symbolic links are supported.
Physical layout of ext2 file system
- Boot sector – Block which may contain the stage 1 boot loader and which points to the stage 1.5 or stage 2 boot loader.
- Super block – The file system header, identifies and represents the file system and provides relevant information about the fs. It must be present at block 1 if a boot sector is present, otherwise at block 0.
- FS/Group descriptor – Pointers to the bitmaps and table in the block group .
- Inode Bitmap – Inode usage information .
- Inode table – Each inode provides necessary and relevant information about each file.
- Data blocks – blocks where the data is stored .
For more information on the project, go through the project report.