Project : Salvage an old hard drive
Discover how to retrieve a disk and its data from a malfunctioning drive
Retrieve data or even extend a disk’s lifespan
it will take
you will learn
How to recover a working hard disk from a failed drive enclosure.
A new external drive enclosure. Data Rescue for possible recovery.
The unthinkable has happened: your external hard drive has suddenly stopped working.
You’ve checked the cables and power adaptor – perhaps using a tool like the LAP Non-Contact AC Voltage Detector (£5.99, screwfix.com) to verify it still works, but your Mac can no longer see it. In this project we’ll look at how you can rescue your disk from a failed drive enclosure, recover data from it if necessary, and then continue to use the internal disk going forward.
The project relies on one key element still working: the disk itself. If the disk still whirrs into life, but gives off an ominous clicking sound, it’s possible it has physically failed (or is failing). In this case, you can still follow the tutorial, but chances are you’ll need to use a third-party data recovery specialist such as Kroll Ontrack (krollontrack.co.uk) to get data off the disk before recycling it.
External drives connect the disk inside to your Mac via circuitry that translates the disk’s physical SATA interface (unless it’s very old) to your Mac via one of its ports – typically USB or Thunderbolt, but sometimes Firewire. If this fails, the disk can’t communicate and you’ll need to liberate it from the case.
Simply replacing the enclosure should suffice more often than not, but if the disk is larger than 2TB or has come from a network drive, there are added complications that we’ll cover in due course. For now, though, let’s focus on getting the drive out of its case.
You’ll need to source a new enclosure to house the disk in. See Best Buys (page 65) for some advice on models to choose. Prices range from as little as £10 for a no-frills portable USB enclosure to over £100 for a Thunderbolt one. As USB is the most ubiquitous choice, we’ve highlighted three solid USB models that are designed to make it relatively easy to insert and remove disks – but that’s not true of your existing drive enclosure.
Prepopulated external hard drives aren’t designed to be user-serviceable, so you’ll
3TB disks may be unusually formatted to be usable with older PCs
rarely find convenient screws holding them together; instead, a series of plastic tabs click the chassis’s various elements into place. Thankfully, others have boldly gone before you and documented the dismantling process on YouTube and other websites. So, your first task is to track down one of these and use it, in conjunction with our step-by-step guide, to transfer your disk from its old case to a shiny new enclosure. Enter the name of your drive’s make and model in Google, such as Seagate Backup Plus 4TB, plus the words “open case”, which should find you a suitable video.
We suggest you watch the whole video before reaching for tools. It’s a good idea to avoid using sharp or metallic objects to prise open the caddy as these can damage it – some experts use guitar picks, but you don’t need to rush out and buy a job lot. Instead, cut up an expired credit card, and then use a rounded corner as the end of your ‘pick’ to prise open the drive case firmly, but carefully.
The moment of truth
Once fitted in its new enclosure, connect the drive to a power source (if applicable) and your Mac, then wait while it’s detected. If it’s a straightforward swap, and the disk isn’t damaged, it should appear in Finder with all your data intact. Congratulations, job done!
However, you may see a message telling you the disk is not readable, inviting you to ignore, eject or initialise it. This means the disk is physically okay, but is formatted in a way your Mac can’t read. Initialising the disk will wipe it, so if there’s data on the drive, you’ll want to recover that first – click ‘Ignore’ if this is the case.
Most disks from network drives use the ext4 format favoured by Linux. If you have a virtualisation app, such as Parallels Desktop, VMware Fusion or VirtualBox, you can create a virtual machine running Ubuntu Linux (ubuntu.com), then connect the drive through that. It’ll show up as readable, and you can then copy data off it to another drive.
Alternatively, you can install a virtual driver that will allow you to read the disk directly in OS X. Start by installing FUSE for OS X from osxfuse.github.io – during installation, make sure you enable ‘MacFUSE Compatibility Layer’ when prompted. After installation, return to the Fuse for OS X website, open the Wiki and select your target
file system from the list – ‘EXT’ is a likely candidate for disks pulled from network drives. You then need to follow the instructions to install the latest version (which is compatible with El Capitan, so ignore the warning) – we recommend installing Homebrew (brew.sh) and following that set of instructions. Although the process completed with errors for us, our ext4-formatted drive was readable in El Capitan afterwards. From here, transfer your data off the drive, then format it in a Mac-friendly format and transfer the files back. Job done.
Recover your data
If your drive is 3TB or larger, it may have been formatted in an unusual way in order to make it readable on older machines. The downside is that its disk can’t be accessed in any other enclosure without first wiping it. Don’t do that just yet; instead, employ the services of the Mac’s best data recovery tool, Data Rescue. Download the free edition from prosofteng. com/freedatarescue and perform a Deep Scan on the entire disk (as opposed to the only visible partition on it) to provide you with a list of recoverable files.
Note that the initial scan can take up to a day to complete, so you may want to start it running overnight and leave it to its own devices. You can click Cancel at any time to suspend the scan, or end it early to see what’s been found on the portion already scanned. However, it’s best to let the scan complete to ensure it finds all recoverable files.
Once analysed, you’ll be able to preview the recovered files before choosing whether or not to pay to recover them. The cheapest method is Data Rescue’s new ‘Paperbyte’ method, where you pay to recover a set amount of data ($49, about £38, for the first 250GB). However, on larger drives, it’s more cost-effective to splash out $99 (£76) for the standard edition, which offers unlimited recovery on up to five drives.
Once you’ve recovered data from an uncooperative disk, you can then reformat it, which enables you to keep using it in its new enclosure going forward. Open Disk Utility (from /Applications/Utilities, or use Spotlight) and select the disk in question – you should find no partitions have been listed on it, making it easy to identify. Click Info to verify this – check ‘File system’, which should say ‘Unknown’. With the disk selected, click Erase to turn it into a HFS+-formatted disk that your Mac should have no problems reading from or writing to going forward.
Network drives often use the ext4 format; data can be recovered using a Linux virtual machine in something like VirtualBox.