I have a LaCie thunderbolt/usb 3.0 external HD that was working perfectly fine up until about two days ago, when my computer (running macOS) would no longer recognize the drive at all.
I don't get any error messages, the drive doesn't show up in DiskUtil at all.
If I check System Information (systemprofiler), a LaCie thunderbolt (or USB) device will be listed if plugged in, but it's not recognized as a storage location.
I have Windows 10 installed on another partition, so I booted that up and tried the drive, but Windows doesn't recognize the drive either (no error messages or anything). It won't show up in Disk Management, but it will show up in Device Manager.
Recovery software seems to be useless, and the drive isn't detected at all.
I booted PartedMagic, and the drive shows only up in the system information as a SCSI Disk with correct manufacturer details, but an error appears that reads "this device hasn't been claimed".
I do have a backup, so I'm slightly less concerned, but any help would be greatly appreciated to try to recover the drive.
Thanks
3 Answers
This happened to me many years ago. At that time I found to my surprise that a disk is detected or not by its stamp, found in the first few bytes in the first sector. If one of these bytes is corrupted, the disk is lost. This is called the Disk Signature.
At that time, I solved the problem by copying these bytes from a similar disk, but I really don't remember how many bytes I copied or using which tool.
I suggest that it would be better to use disk rescue tools to fix the first sector.
TestDisk might do the job,
as explained in the article
How To Fix: External Disk Drive Suddenly Became RAW.
TheNTFS Data Recovery Toolkitis another possibility, but others such products do exist.
For more information and some manual methods see :
It seems the partition map of your external hard drive is damaged badly and Disk Utility doesn't repair the map though you can erase your ext-HDD afresh and map a new partition map on it.
It's good you already have the backup and data recovery isn't your priority here. Usually, people ask for the data recovery from such a drive.
I am interested to know how data recovery application didn't help you? Some tools can recover data from a troubled or unmounted volume. Do let know.
I had this happen with a Lacie Thunderbolt 2 5BIG RAID on Mac OSX High Sierra. The only connection I had with the drive was a Lacie CLI utility that successfully updated the RAID Controller's firmware. Lacie Raid Manager did not see the drive at all. Lacie support (which is now Seagate because of the acquisition of Lacie by Seagate) had no suggestions. I called Apple tech support, and we realized that the problem started after the latest High Sierra security update. After rolling back the High Sierra installation using Recovery Mode and reinstalling High Sierra, the drive appeared again and passed all consistency checks. So there is something in this update: that prevents the drive from being recognized. Hope this helps.
