Wipe free space on SSD and HDD

[selsunblue]

Hi, 

ccleaner warns me that I should not use the wipe free space feature on ssd's since it will be bad for it. But then how do I get rid of free space on my ssd, where my windows is installed?. I heard you can do it manually but that's gonna take ages. I also read from other posts on this forum that ccleaner would do it for you even if you don't specifically select the ssd. Is there a way I can look at the files to ensure they're deleted permanently. A couple things I noticed from other forum posts is this thing called TRIM. What is that exactly and how do I enable it. If there is a known solution to this can you link me to the process, because I haven't found many other convincing solutions to this.

Thanks.

[Willy2]

- Indeed, it's better to keep the amount of write operations (that includes "Wipe Free Space") on your SSD as low as possible.

- But if you REALLY want to use the "Wipe Free Space" (sparingly) on your SSD then don't let that warning deter you.

[Augeas]

I don't agree with you Willy as - apart from the wear on the SSD - wiping free space cannot possibly achieve what it is trying to do as you cannot physically overwrite an SSD page.

To the O/P, TRIM is an inbuilt function that tells the SSD that deleted pages are no longer required. If your SSD and PC/laptop are no more than say, five years old then TRIM should be available and enabled automatically. With TRIM there should be no deleted files in free space as the pages are emptied by the SSD controller.

However TRIM is not infallible and occasionally some pages (deleted files) are left in an SSD's free space. To get rid of these you can run an Optimise from either Window's defragger or Piriform's Defraggler. This in effect runs a TRIM on the whole SSD and removes any deleted files there may be in free space.

Mnay of your questions can be answered (far better) by Google or Wikipedia.

[ccw62]

Up front: I know this subject is discussed over and over, here and elsewhere on Internet.
Also I  know that TRIM should do the job, so it is not necessary and will wear out the SSD.

That said... when it comes to privacy and whilst running recovery tools like Recuva (deep scan):
TRIM will not touch the folder paths of deleted files, meaning that even though a file and/or folder is deleted
and even with TRIM being active and even if the file is not recoverable anymore, Recuva will still show details
i.e. the nature of the file(s)/folder(s)...

A wipe free space solves this.

Modern SSD, especially the more expensive ones, are quite durable and have a lifespan of many years.
They often run idle most of the times.
Probably running an occasional wipe free space (say a few times a year) won't really wear out the drive too much.
Often users will buy a new PC every, let's say,  4,5 years or so.
 

[Augeas]

Yes, it has been discussed endlessly, mostly by people whose knowledge is, or was, HDD based (and I'm one of those too). We can more or less figure out what happens on a hdd when a wfs is run, but who knows what an SSD controller is doing?

As I'm sure you know, a TRIM (or a defrag Optimize) won't get rid of file or folder names and paths, because these are held in the MFT, which will never be trimmed. A wfs using Drive Wiper runs a wipe MFT first, and overwrites the deleted records in the MFT by allocating enough small files to fill all the unused records. This is a ham-fisted way of wiping the MFT as it involves two separate page writes (allocate and deallocate) to the MFT bitmap block, two to the offending MFT file record, and at least two to the owning folder. So a wipe MFT could write thousands of SSD pages, but there is no other method that I or Piriform know of to get rid of those file names.

It's a pity that the wipe MFT function is not available separately, as a wfs must be the complete pig-fisted way of wiping the MFT. The actual wipe free space process is superflous to wiping the MFT and a defrag Optimize will do the wfs part far more efficiently than CC's wfs.

There's no real answer to your problem, except mine which is to ignore the file names and stop worrying. Who is going to run Recuva on your device to see what files you have deleted? There are so many other things to be paraniod about.

 

[ccw62]

Thanks!

I agree, there a lot of other things to worry about... 

That said, often there is no need to wipe the entire HDD (or SSD), but wiping some files or folders, including their MFT entries, that would be convenient sometimes.
Specifically this (file erase and wiping its MFT record), often is not listed in the 'feature-list' of file wipers/shredders.
I believe Eraser can take care of that and BCWipe (Jetico). The BCWipe tool wipes so-called 'Directory slacks' and "NTFS transaction log file" as well, and MFT records.

Anyway, thanks again.