A common problem which users suffer is the accidental or malicious, deletion or reformatting of a hard drive partition. When this happens, it is important not to panic and make an ill considered attempt to recover the deleted data, which could compound the issue, even leading to total loss of data.
Partition Only Deleted
The deletion of a partition need not be disastrous, but it is important not to make a further mistake. The use of free do-it-yourself utilities are not guaranteed to recover your data, and in the worst cases could cause damage. This is particularly true when the deleted data volume is a spanned or striped set of partitions. Some users erroneously believe that after the deleting a data volume, they can gain access to the data by recreating the partition, but this leads to the partition being reformatted. Once you make a mistake, do not compound the issue by making a rash decision.
Once a partition has been reformatted, the consequences can be anything from only minor damage, to complete loss of data. Copying data to a newly reformatted partition will compound the issue further, by overwriting important system areas of the volume.
Can I Get My Data Back?
The answer to this question is not simple, as it depends upon a couple of very important factors, such as the file system, and the volume of any data written to it afterwards. Many file systems when they are formatted, overwrite the most important system areas of the volume that are required to allow the retrieval of the old data; this includes many Unix and the HFS+ file systems.
The good news is that for NTFS and XFS file systems, an almost complete recovery of the old data may be possible, although writing new data to the volume will diminish the quality of the results which are possible. This is known as Unformatting, a process which our data recovery software at DiskEng has performed many times with excellent results. FAT file systems can also be Unformatted, but the quality of results is also affected by how much fragmentation was present in the files held on the volume.