How To: Recover Deleted Data on a Mac Hard Drive

Editor’s note: This is a guest post by Ray McAllister. If you would like to contribute too, please contact me.

Recovering data from your Mac could be a difficult task when the Trash folder is emptied. In many cases, undeleting a file on your Mac may lead to only a partial recovery of your files and folders. The simple truth is that it is really not an easy task to undo something that is permanent.

It has been pot raid in movies that you can do anything on a computer, even recover lost data with a few button clicks. However, there are steps that may be taken to increase the likelihood of a partial recovery.

Check the Trash (Folder)

Once you realize that you deleted a file that you really want to keep the obvious first step to take is to check the Trash Folder for the accidentally deleted file. The Trash folder in Mac OS X is really a private, hidden directory located in each user’s Home folder. The default path to the trash folder is ~/.Trash. If additional hard disk drives or USB sticks are attached to the machine, those drives contain an invisible directory called .Trashes, which in turn includes a hidden Trash folder for every user.

An important note to keep in mind is that after the trash is purged, even though you believe that the file is deleted, in actuality the remnants of the file are not overwritten immediately. The hard disk space occupied by deleted files is considered free hard disk space by OS X. As soon as you start adding new programs and adding new files the OS may use this disk space for the new data, thus totally destroying the original data.

If you used the Empty Trash Securely option and it was enabled, it is highly unlikely that any data could be restored. The reason why file recovery is impossible with Empty Trash Secure is because the drive data is overwritten many times to make sure there is no possibility of recovery. A true sign of security software.

Getting back to the topic on hand, if you did delete a file you need back. The next matter to do would be to minimize the write activity on the hard disk because anything added after this could be written to the freed up space. The best option would be to unplug from the internet and to not run any applications until you recover the lost data.

Free Built in Data Recovery

The dd command on Mac OS X and UNIX is used to copy part of a drive partition or a whole hard drive bit by bit. It’s installed with virtually every UNIX and Linux OS as well as Mac OS X. The dd command itself won’t recover data; however it may be used to create a picture backup of each and every byte about the hard drive, including the free space which has deleted files.

One thing to keep in mind about backup utilities is that they will not backup the free space which was once occupied by data. Even though the data is still there is will stay there until new data is written over it.

Another term for the dd command is “disk destroyer” because it will do exactly that if you are not careful with it. Be sure that is what you want to do before doing so. The reason for that nickname is because when the command is typed incorrectly, it could overwrite the incorrect hard disk. If a dd clone of hard drive is created, some disk recovery programs may be capable of browsing the dd image. Unencrypted EnCase and CopyCatX images can often be used as well.

Using Mac Data Recovery Software

To use any Macintosh file recovery software, this work by booting the system through the recovery bootable DVD instead of to OS X. Once the data recovery software programs are running, the program begins to look for deleted files and asks the consumer which files to restore.

Deleted data must be written to a separate partition or USB stick. If recovered information is written on the same partition, it may start overwriting the information that’s in the process to be restored. There is no guarantee that files recently deleted will be the last to become overwritten. Another option would be to burn the found data to a DVD disc by using a compatible Mac DVD burning software.

Many Mac file recovery software have free trial modes where the user can scan for their deleted files free of charge to make sure it works. Purchase is required to actually salvage the file. It might be better to keep trying different software until one of them finds the deleted file.

Using a Hard Drive Recovery Service

If the records data can’t be retrieved by utilizing Mac file recovery software, then your only other option is to hire a data recovery service with Macintosh experts.

The task typically calls for removing the hard disk containing the deleted files and sending it to get looked at and recovered by Mac professionals. The hard drive will then be delivered back to the individual together with the restored files. CBL Data Recovery Technologies and Stellar Data Recovery are two such organizations devoted to the operation of Mac file recovery.

While Mac data recovery services are significantly pricier compared to file recovery software, most legit data recovery firms will not charge any fees in the rare and unfortunate situation where the deleted files can’t be retrieved.

Final Notes on Preventing Data Loss on Mac Computers

Taking into account that all hard disk drives gradually fail, the best approach to prevent data loss on Macintosh computer systems is always to regularly backup essential files and data to DVD discs or to USB sticks. The best option will be to have a reliable (and preferably automatic) daily backup system available.

It’s also essential to have multiple data backups in different physical locations to prevent against loss of data due to fire, flooding or theft. Remote online storage is a common solution. There are actually a large number of companies devoted to online data storage. For example, many Mac users benefit from Apple’s MobileMe online service specifically for the included option of remote data storage.

Even with these preventative activities, unexpected data loss is a fact of life for Mac computer users. Nevertheless, it is good to know that most cases of data loss can be fixed by Mac data recovery software or a data recovery service specializing in Mac systems.

Guest post: This article is written is by Ray McAllister who is a guest writer for www.burnworld.com which is a DVD & Blu-ray Burning info site.