Macintosh operating system is a very powerful operating system with lot of advance features like it supports a number of storage media like USB drive, hard disk,CD, DVD, external hard drive, USB drive and memory cards to store your important data. The external hard disk is basically used to take backup of your valuable data and to safeguard your data. It can also be used to transfer data from one machine to another. However, in some cases, the external hard disk may become inaccessible and critical data loss situations arrives. At this point of time, you need to perform Mac file recovery to recover all the data.
Sometimes, Macintosh OS X fails to read the external hard drive. When you attempt to extract data from an external hard disk, The below error message is displayed
“The disk is unreadable: Do you want to initialize it now?”
After that if you try to repair the error using the disk utility the following error messages are displayed
“Verify and Repair volume “disk1s3”
Checking Journaled HFS Plus volume.
Invalid node structure
Invalid B-tree node size
Invalid node structure
Invalid B-tree node size
Volume check failed.
Error: File system repair failed.”
As described in the first error message, your Mac OS X hard disk needs initialization. But this process removes all your valuable data from hard disk.
If you fail to replace the damaged system files without formatting hard disk, you need to use Mac file recovery software to retrieve lost data from hard drive.
