Recovery of data from a formatted disk Disk formatting

as in file deletion operating system, data on disk not erased during every high-level format. instead, area on disk containing data merely marked available, , retains old data until overwritten. if disk formatted different file system 1 existed on partition, data may overwritten wouldn t if same file system had been used. however, under file systems (e.g., ntfs, not fat), file indexes (such $mfts under ntfs, inodes under ext2/3, etc.) may not written same exact locations. , if partition size increased, fat file systems overwrite more data @ beginning of new partition.

from perspective of preventing recovery of sensitive data through recovery tools, data must either overwritten (every sector) random data before format, or format program must perform overwriting, dos format command did floppy diskettes, filling every data sector format filler byte value (typically 0xf6).

however, there applications , tools, used in forensic information technology, can recover data has been conventionally erased. in order avoid recovery of sensitive data, governmental organization or big companies use information destruction methods gutmann method. average users there special applications can perform complete data destruction overwriting previous information. although there applications perform multiple writes assure data erasure, single write on old data needed on modern hard disk drives. ata secure erase can performed disk utilities , thoroughly wipe drives. degaussing option; however, renders drive unusable.