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Freespace Wiping

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 CCleaner Version: 1.17.60. Mac IOS 10.14.6.

Hi Folks,

I am currently utilising the "Wipe Free Space" utility with a 7pass run, this has been working for over two whole days so far is this correct to take so long? it has completed the 7 passes , is currently on 

"Creating A Secondary Temporary File" which is on its fifth pass. my hard drive is only 499 GB. any advice will be much appreciated.



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Wiping Free Space can take a long time, days, as you are finding out. And of course the bigger the drive the longer it will take.

It has to write random data to every bit of free space on the drive, and then delete it again.

And you've told it to do that seven times.

There is no need for multiple passes, one is entirely sufficient.

So why does CC offer multiple passes?
It's simply a hang over from the old days.
Multiple overwrites may have been desirable back in the 1990's (even that's debatable), but they are not required with modern drives.
Have a read of this article:

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  • 2 weeks later...

Days??? The warning instructions said it could take several hours, not days. Mine has been running now for almost 24 hours. Had I know it might be days running, I would not have done this. Also, Nukecad, or others, what is the security setting "zero out" mean compared to 7 passes? Thank you.

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12 hours ago, Mjfuller said:

 what is the security setting "zero out" mean compared to 7 passes?

I'm not sure what you are meaning? Where can you see "zero out" as a setting?

I only see the following:


"Zero Filling" a drive is a different thing to wiping free space.
Zero filling is a disk formatting technique that overwrites everything on the drive, not just the free space.

The equivalent in CCleaner is selecting "Entire Drive" to wipe rather than "Free Space Only".
CCleaner will not let you select "Entire Drive" for the system disk (usually C:) because that would remove everything including the Windows operating system..

See this: https://www.techopedia.com/definition/10143/zero-filling

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Nukecad: here is a screen shot of my Ccleaner window. Notice the Security window that shows the "zero out" option. The other options were 7 passes or 35 passes. It finally stopped running and completed it's erasing after somewhere  between 24 and 48 hours. 



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Ah, my apologies.
I was looking at the Windows version not the Mac version.

The Mac version has the three options - Single pass, 7 pass, and 35 pass.
Note that a lot of the CCleaner documentation is somewhat out of date and they are working on rewriting/updating it.

It would appear that 'Single pass' has been renamed to 'Zero out' in the Mac version of CCleaner. (Because that's what Mac's own Disk Utility calls it).

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