I have My Book Essential 2Tb.
When I do reformatting disk it looks ok and I start to use it for Time Machine backup. First backup (about 500 Gb) usually done succesfull but next sessions ends with error message then I start to verify disk in Disk Utility and always see the same strings:
Verifying volume “Backup”
Checking file systemChecking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Checking extended attributes file.
Checking multi-linked directories.
Checking volume bitmap.
Volume bitmap needs minor repair for under-allocation
Checking volume information.
The volume Backup was found corrupt and needs to be repaired.
Error: This disk needs to be repaired. Click Repair Disk.
After that I repeat all operation (formatting and full backup) and face this problem again and again.
So I suppose there is perhabs two problems:
Power supply issue causing controller problem
Is there any way to detect problem exactly?