Thing is, that depends on the filesystem. I know that the usual shred commands don't work all that great on Ext4 due to journalling and such, but Microsoft actually provides[1] a first party tool to do it on NTFS (at the file level) to handle those edge cases.
Apple provides[2] a built-in free space nuking tool as well.
That leaves sector reallocation by the disk controller, but doesn't that only happen if data can't be properly written in the first place anyways?
Thing is, that depends on the filesystem. I know that the usual shred commands don't work all that great on Ext4 due to journalling and such, but Microsoft actually provides[1] a first party tool to do it on NTFS (at the file level) to handle those edge cases.
Apple provides[2] a built-in free space nuking tool as well.
That leaves sector reallocation by the disk controller, but doesn't that only happen if data can't be properly written in the first place anyways?
[1]: http://technet.microsoft.com/en-us/sysinternals/bb897443.asp...
[2]: http://support.apple.com/kb/ht3680