Refuses to shut down after free space erase

[Thindows]

Hi, and thanks for the great Eraser tool. It was amazing how much free space was reclaimed after the first erase, from debris you don't even know is still on the machine.

My problem is that although I have configured "Unused disk space" > Properties > When finished > "Shutdown system", this shutdown *never* happens. I usually run this task overnight, for obvious reasons, yet the next day, the task is completed properly, but the machine is still powered on. I look in the Properties\When finished and find that it has changed itself back to "None". Please tell me how I can make this choice sticky and effective. Thanks!

Win XP SP2 Home
Eraser 5.86.1

 

[Overwriter]

Hi Thindows

It was amazing how much free space was reclaimed after the first erase, from debris you don't even know is still on the machine.

Eraser only overwrites files you tell it to. To delete temp files, cookies etc use Ccleaner until Eraser V6 is released.

My problem is that although I have configured "Unused disk space" > Properties > When finished > "Shutdown system", this shutdown *never* happens.

I seem to remember others having the same shutdown problem but I can’t find it just now. I think this may have to wait until Eraser V6 I’m afraid.

You can use a single pseudo random pass which will be much quicker than the other pass options so you could perhaps run Eraser through the day on a lunch break for example.

 

[Thindows]

Eraser only overwrites files you tell it to. To delete temp files, cookies etc use Ccleaner until Eraser V6 is released.

I haven't read the documentation thoroughly enough yet, especially regarding Cluster Tips, but I intend to soon. All I know is that after running a full Free Disk Space erase, the hard drive always shows fewer GB used than before the erase. As mentioned, this was dramatic the first time, but with regular use, it seems to shrink the disk usage maybe 100-200MB. Go figure. I'm not complaining! (My uneducated guess is that Windows does not necessarily return all so-called "deleted" files to available disk space, or maybe it doesn't regard the rest of the cluster as available. Maybe it prefers to write to completely empty space first? After Eraser, Windows realizes, "Duh, that space really *is* empty"! But that's just a SWAG).

My problem is that although I have configured "Unused disk space" > Properties > When finished > "Shutdown system", this shutdown *never* happens.

I seem to remember others having the same shutdown problem but I can’t find it just now. I think this may have to wait until Eraser V6 I’m afraid. You can use a single pseudo random pass which will be much quicker than the other pass options so you could perhaps run Eraser through the day on a lunch break for example.

Certainly. Just looking for the higher security from time to time. It's not that big a deal, as I've found that either 7-pass option takes 7-9 hours, so if started right before sack time, it won't have been running for very long when I get up. Haven't had time to do a 35-pass Full Disk yet -- maybe while on vacation.

Thanks for the reply. Looking forward to V6!

 

[Overwriter]

Certainly. Just looking for the higher security from time to time.

This has been discussed many times on here. To briefly summarise, if your hard drive is reasonably modern then a single pseudo random pass with Eraser should be all you need. The other more exotic wipe patterns were created at a time when the write heads on a hard drive weren’t as accurate as they are now. I just don’t want you to be wearing your hard drive out for very little additional security gain, if any.

The single pass will defeat all software recovery programs without doubt. If your adversary has an electron microscope I believe you are still safe, but you might want to make 2 passes if that’s the case ! :lol:

If you want to significantly improve your security then I suggest you use Truecrypt and encrypt your entire OS. Plain text never hits the drive surface so there is nothing to overwrite ! :wink:

Looking forward to V6!

Yeah, so am I !!! It has been a long wait.

 

[Thindows]

if your hard drive is reasonably modern

Is 2005 "reasonably modern"?

I just don’t want you to be wearing your hard drive out for very little additional security gain, if any.

Neither do I. That's great to know -- thanks!

If your adversary has an electron microscope

LOL! I sincerely doubt that I have anything that would be of interest to NSA or anyone at that level :wink: Just the usual -- passwords,etc.

Truecrypt

Yes, I already use it to protect some files, and like it very much.
I had one other guess about why the HD usage size shrinks after free space erase. Eraser erases directories and unused MFT entries, correct? Maybe Windows doesn't regard the space that was alloted to those directories as "free" until the directories are erased. And I understand that some very small files (e. g., .txt < 1k) are just stored in MFT, cuz it takes less space than establishing the MFT entry itself would. Maybe those don't become available until E erases the old MFT entries?

Not that any of this matters Have a great day,
T.

Edit: Aha! Just found out why E causes increase in free space!
E Help > Advanced Topics > Abstract > Overwriting Properly:

"If one overwrites only the free space available on a drive, the cluster tip area still remains untouched - this is why Eraser overwrites also cluster tips when overwriting unused disk space or single files. "

Isn't this saying that the unused cluster tip from a file is *not* regarded as free space by Windows? And when E erases it, it is. After several years, you'd have a lot of cluster tips out of your million or two available clusters. If E picked up 1-3k each, there's another GB or two of free space. Cheers!

 

[Overwriter]

Is 2005 "reasonably modern"?

Certainly, I am talking early 90’s !!! :lol:

Yes, I already use it to protect some files, and like it very much.

You can protect the entire OS now with V6.

Isn't this saying that the unused cluster tip from a file is *not* regarded as free space by Windows? And when E erases it, it is. After several years, you'd have a lot of cluster tips out of your million or two available clusters. If E picked up 1-3k each, there's another GB or two of free space. Cheers!

I’m not sure but you have a good explanation there, well done ! :wink:

 

[Joel]

Nope that's a wrong conclusion. Take this disk layout for example:

Logical cluster: | 1 | 2 | 3 | 4 |
Within logical cluster 1: | byte 1 | byte 2 | ... | byte 4096 (usually) |

So there are 4096 bytes in a logical cluster. Files don't end up having sizes with multiples of 4096, so assuming your (file size mod 4096) = 2 (modulo arithmetic) , bytes 3 through 4096 will be "empty". The file ends at byte 2, but the remaining 4094 bytes can't be used by the OS, so that's your slack space. It's not space clusters at the end of every file; files only occupy as many clusters as they require (excluding this 'slack space')

I believe the space you gained was from Windows deleting your old System restore entries. Windows does that when your disk runs low on disk space. That saves a few hundred GB in my case some times (with my 500GB data disk)

Joel

 

[Overwriter]

That’s interesting, thank you for the explanation. :wink:

I was going to make some suggestions for V6 here but it all got a little too complicated and so I talked myself out of it ! :lol: