R-Undelete is a powerful file undelete and file recovery software to find and restore lost files on a disk, USB, memory stick, SD card. Free R-UNDELETE version for Home Users recovers files from external USB disks, digital photo and video camera memory cards and other R-Studio for Mac.

This post is sponsored by MacPaw, maker of CleanMyMac. Deleting, erasing and partitioning On the Macintosh moving a file to the trash, then Emptying the Trash, deletes the item. When you delete a file or folder you remove the entry for that item from the disk directory. Immediately after deletion the data still remains on the disk where it was but the directory says “that space is vacant.” As long as you don’t write anything new to the disk, recovery is usually straightforward. If you accidentally delete something you need, if at all possible stop using the affected disk immediately.

Another way to delete a file is to use Apple’s Disk Utility to Erase a drive. By default Disk Utility does a Quick Erase, which just deletes the disk directory and replaces it with a new empty copy. The underlying file structure on the volume is not changed, and any existing data remains in place until it gets overwritten. Partitioning a disk removes all existing volumes on a device, then creates new ones with new disk directories. However like a Quick Erase, Partitioning doesn’t actually remove underlying data, it just marks the space as available.

File recovery is usually possible on re-partitioned drives, though this will require a more thorough scan than with a standard erase. A Secure Erase – typically a multi-pass process – writes new data to the disk and is deliberately destructive to old data. The utilities described here will not work if a Secure Erase is performed on your disk, recovery will require a forensic data recovery service. Undeleting files on Mac All Undelete utilities require use of a separate recovery disk to which are copied recovered files. The recovery disk needs adequate free space for the expected amount of data.

Access hard drive on mac. A hard disk, flash drive, another Mac in Target Disk Mode, or even an iPod, can be used to store recovered files. There are a number of utilities available for this task, the two I’ve relied upon most are. Both are often worth having around in crisis situations, sometimes a few files will be found by one but not the other.

You are usually given the choice of a different levels of scanning, from Quick Scans for recently erased files, to Full Salvage operations for erased or damaged drives. If you know the kinds of files you are looking for, that can speed things up. It’s usually worth trying the quickest options first, then increase the scan levels as needed if you don’t find what you need. Recovery programs typically work in two passes, first scanning the drive to see what it can find, then recovering the data. This can take minutes, hours or days depending on the size of the drive, number of files to recover, and condition of the media; a damaged or slow disk can substantially slow down the process.

Scanning the drive takes about the same time with both programs. FileSalvage display the tally of found files in real-time, Data Rescue utilizes a post-scan parsing. The result is typically a huge number of recovered files sorted by file type – Documents, Audio, Movies, Pictures – but no filenames!

It’s nice to get a thousand Microsoft Word documents back, but not very helpful when they’re named D3464.doc, D3465.doc, etc. Similar results happen for all file types:.xls,.pdf,.jpg,.tif,.mov, et.al.

We’re really only halfway there Recovering lost Mac filenames Why are filenames lost when recovering data? After a particularly challenging recovery job I posed this question to both ProSoft and SubRosaSoft tech support. Here are the responses I received from each company: ProSoft: It’s most likely a problem resulting from the reformat which wiped out the old file catalog. A lot depends upon the type of file and the program which created it. Some programs embed metadata (in the case of MP3’s, they are called ID3 tags, in the case of camera images, it’s called EXIF data) which may contain the name of the file, but that does not hold true for each and every file type.

SubRosaSoft: The file names will not be included as they are not actually stored in the file but rather in the system’s catalog/ b-trees. As soon as the file is deleted, the information will be removed and the space recycled and overwritten. FileSalvage will recover your files to the folder of your choice but the specific folders they were in and placement will not be the same. This outcome can be anything from a minor inconvenience to a major headache, depending on how many files you have. Other than opening and renaming each file individually, what are the options? One nice bonus with FileSalvage: after recovering files the program asks if you would like to attempt to rebuild filenames.