Disk warrior has long been a favoured utility used by mac support companies and enthusiasts to analyse and repair Macintosh volumes. It is favoured mainly for it’s simplicity and many features including data recovery.
As a data recovery company we have received many mac hard drives from clients who had previously used Disk Warrior to attempt to gain access to their data.
In some cases the particular hard drive being examined was too severely damaged for Disk Warrior to be of any use. In other cases Disk Warrior was used but the data left afterwards was corrupt and not accessible.
This article is to hopefully make people aware of the downside to using a powerful utility such as this, especially when your lost data is critical to you.
The problem is not so much the utility itself, but the lack of a users understanding of how powerful this utility is. This is a quote used on Alsoft’s website that can be misleading.

“ Simply click the rebuild button and Disk Warrior goes to work ”

In any data loss situation writing to the hard drive that has your lost data is something that should never be carried out, as it is this writing process that can do more damage that good. Disk Warrior uses this process when rebuilding mac volume structures and in cases when it gets it wrong, the consequences can be catastrophic for the end user. It often results in the rebuilt data left behind being damaged and not accessible.

We recommend that you read the documentation that comes with the utility carefully and fully understand it’s capabilities.