On Sun, 16 Nov 2014 12:04:31 -0700 jd1008 wrote: > Before sending the drive for warranty service, what is the best way to > clean the unallocated blocks? A way is to run as root "cp /dev/zero tempfile" for one "tempfile" per partition until the cp fails due to running out of disk space. That will allocate all free space and write zeroes to it.