Another product I believe does something similar + call it ‘secure underwriting I do not think this would be a good idea. Say you have a file 5136 long and a cluster size of 1024.
Just for that file you can clear the tip. Supposing you edited a doc that went 5136 -> 6136 -> 5000. This means the clusters used will no longer be on the tip of the file.
The only sure solution is to erase the entire free space.
However, with large hard drive sizes these days (and only getting bigger), it is common for partitions to be many gigabytes in size. As such, wiping the entire partition is a very long and strenuous process (both for the hard drive and the user).
Lets take the case where you create a small text file to store some notes. Perhaps you call your bank, and get some info. You type in the banks name, their phone number, your account number, and your secret code to access your account. You then save the file. Well, a couple minutes later you decide to delete your secret code from the file, but keep the rest of the file. So you delete the code, and save the file again. Of course, the code is still right there after the EOF mark (if your text editor even adds an EOF!) even though you "deleted" it. Youre a knowledgeable user, so you know that a few hundred bytes isnt ever going to cross a cluster boundary. But there is no simple way with eraser (right now, at least ) to erase that slack space without wiping the unused space on the partition and the slack space of EVERY file on the partition. That could literally take many hours (or even a day or two if there are a lot of files).
The only alterative at this time is for the savvy user to create a new file, copy all the data from the original file, save the new file, and then erase the first file (and erase its cluster slack space as well). Whew! Thats a lot of work. And if its not a plain text file, youll have to use a hex editor to make the copy.
The above is just a simple example, but Im sure you can think of others.
Because wiping cluster slack space of ALL files in a partition is such a time consuming process (and must wear the hard drive a fair amount), I imagine that most people leave that option turned off a majority of the time (and just use it occassionally or on partitions with just a few files). But most people have a couple files that they want to be sure have nothing hiding in the slack space. It would be a great addition in eraser to be able to just erase the slack space for the specific files that need it. In other words, first erase all the unused space in a partition, and then erase the cluster slack space for only the few specific files that warrant such protection. It could wind up saving people a significant amount of time, and help lengthen the MTBF (mean time between failure) of users hard drives.
The above logic (hopefully its logical ) forms the origin of the suggestion: have an option to just erase the cluster slack space for a selected group of files.