Crashed Hitachi XL1000 external drive
How can I retrieve data on a crashed external drive?
Question marked as
Retrieve the data from a backup.
If the hard drive is failing, then contact a professional data recovery service such Drive Savers or Ontrack. Both vendors provide free estimates and both are recommended by Apple. You may only get once chance to recover data from a failing hard drive.
You can attempt to check the health of the external hard drive by using DriveDx. You will need to install a special USB driver in order to attempt to access the health information on the external drive. However, even with this special USB driver it may not be able to access the health information on the external drive since some USB controllers on external drives does not allow the necessary communication to access the drive's health information. Post the complete DriveDx report for the external drive here using the "Additional Text" icon which looks like a piece of paper.
If the hard drive is healthy, then you can attempt to run Disk Utility First Aid on the drive. If the volume won't mount, then try running First Aid on the hidden Container and on the physical drive. First Aid won't be able to fix a failing drive and may make the drive failure worse so it is very important to first make sure the drive is healthy. You can attempt to use data recovery software such as Data Rescue (some of it may work even if the drive is unable to be mounted).
What file system is on the external drive and how was the drive being utilized?
Have you tried connecting the drive directly to the Mac? Does the external drive have or need its own power supply? Try using another cable and try connecting the drive to another port.
You should always have frequent and regular backups of your computer and any external media that contains important and unique data.