[v5, v6] Why does it take so long to overwrite free space?

Overwriter

Active Member
When you use Eraser to overwrite a file Eraser actually has to write the same amount of data as the target file size. This means that if you overwrite a 1GB file Eraser has to write 1GB to overwrite it. However this is only true if you select a single pass, should a user select the Gutmann method for example to overwrite a 1GB file Eraser has to write 35GB as the Gutmann method requires a 35 pass with various patterns.

So, when you overwrite your free space think about how much free space there actually is. It could be huge with modern hard drives. If you do have a lot of free space and you wish to overwrite it I personally recommend a single pseudorandom pass with Eraser, as far as I know there as never been any successful recovery of overwritten data on a modern hard drive after a single pseudorandom pass.

If you have a very large hard drive and wish to overwrite your free space regularly I suggest you make some “ballast” files to occupy the free space so there is less for Eraser to wipe. When you need more space on your drive simply delete one of your “ballast” files and continue.
 

greyowl

Member
Re: Why does Eraser take so long to overwrite my free space ?

Thanks for the explanation.

How do you make a ballast file?
 

Overwriter

Active Member
Re: Why does Eraser take so long to overwrite my free space ?

Hi greyowl

You can make a ballast file out of anything you like really. Perhaps you have some DVD films you could use to make backups and store them on your hard drive.

I personally prefer to make Truecrypt file volumes because I can make them exactly the size I want. You could make some bulky 10 – 20 GB ones to take up most of the free space and then make some smaller 1GB ones for fine tuning the amount of free space you wish to have available.

I did make a feature request for this feature to be added to Eraser V6. The ability to make random files of a user specific size just for this purpose but there seemed to be little support for it.
 

greyowl

Member
Re: Why does Eraser take so long to overwrite my free space ?

Thanks for the explanation.

I presume that after creating a Truecrypt file you can remove it in the future to provide needed space.
 

Overwriter

Active Member
Re: Why does Eraser take so long to overwrite my free space ?

greyowl said:
Thanks for the explanation.

I presume that after creating a Truecrypt file you can remove it in the future to provide needed space.
Yes you can. :)
 

Joel

Active Member
It replicates what Eraser does on an unused space erase without cluster tips being erased; Eraser however is more secure as directory entries are erased (for NTFS, and FAT under XP), though yes that application is useful for creating a ballast file.

Joel
 

Unregistered

New Member
What about partitioning instead of ballast files? If I have a huge harddisk (1-2TB) which takes 20 hours to erase, wouldn't it be better to split the HD into smaller partitions, so one day I can erase the first partition, next day the second... and so on?
 

Joel

Active Member
that works. But ballast files allow you to grow your partition in the event you run out of space. Also not everyone is familiar with the process of repartitioning.

Joel
 

seglea

New Member
Re: [v5, v6] Why does it take so long to overwrite free spac

How long is long? Mine's been running for over 12 hours now, trying to wipe a half-empty 80Gb disk on a 6-year old Pentium 4 - is this normal, or has it jammed somewhere?
 

Joel

Active Member
Re: [v5, v6] Why does it take so long to overwrite free spac

What does it say for progress when you double-click on the running task?
 

mrmagic

New Member
Re: [v5, v6] Why does it take so long to overwrite free spac

my unused disk space erase has been running for 48 hours. Progress says: 90%, pass 3 of 3 Old resident system table files. Should I cancel the erase?
 

Joel

Active Member
Re: [v5, v6] Why does it take so long to overwrite free spac

How much disk space do you have left?
 

mrmagic

New Member
Re: [v5, v6] Why does it take so long to overwrite free spac

drive is 585 gig, with 15 gig free space
 

mrmagic

New Member
Re: [v5, v6] Why does it take so long to overwrite free spac

would deleting some of the files in the pseudonamed folder help?
 

DavidHB

Active Member
Re: [v5, v6] Why does it take so long to overwrite free spac

mrmagic said:
would deleting some of the files in the pseudonamed folder help?
No, because, even if it could be done while Eraser was running (I haven't tried), that would free up space that would have to be overwritten all over again.

Was the 15GB you mentioned the figure when Eraser was running? If it was, how much free space do you normally have?

I would cancel the erase, do a drive check, and then try again as my first attempt at a fix.

David

PS. If you need to continue this discussion much further, I may split the thread, and move your query to the main support forum, as your problem is not really about the time it generally takes to complete a free space erase.
 

j.c

New Member
Ok, so I have a question. Or a few questions...

I downloaded this eraser from FileHippo coz I wanted something that would erase free space as well as files/folders.

My laptop recently crashed (blue screen of death), so I took my laptop, my 500GB external hard drive and myself to a computer tech wizard who also happens to be a friend.

As far as I know, my friend a) recovered as much as possible from my laptop onto my external hard drive then b) completely wiped and rebuilt my laptop then c) reloaded all my files onto my laptop from my external hard drive.

I'm now needing to use my external hard drive for a different purpose, and so was going through all the stuff on it to see what I could delete. In the process of doing that, I found a whole bunch of stuff on my hard drive from my tech-wizard friend. Stuff from his business, financials, all sorts.

I went through and deleted all the files off, then did a memory disk format, but in doing that I remembered a conversation he and I had about security and how deleted files are still there. Hence my realising my need for Eraser.

However, I'm not so keen on the speed of operation.

I first started it at 4pm on Friday afternoon. By 10am Saturday, 18 hours later, it was still trying to determine the cluster thingy, with no idea of how long THAT process would take (Time: Unknown), or if it was even actually doing anything. For all I know, it could have been stuck.

So, I stopped that process, unchecked the cluster option, and started it again just with the Gautman 35 pass. That was started around 10am today, not long after I stopped the first one. At 10pm, that is, 12 operating hours, it had only done 2% of the disk space. That is, 1% each 6 hours. At that rate, it's quoting me 25 days to complete the erase.

Is this normal? Should it really take that long? It's erasing at the speed of 1GB per hour. I'm no tech expert, but even with 35 writes and deletes, that still seems like an awfully long time...

Should I stop this erase and choose some other settings?

(I've also read the post about cluster tips, but if it's going to take me 25 days just to erase the free space, I don't know that I want to add unknown more days by including cluster tips... But if that's important, maybe I should do that too. And put my computer and hard drive out of action for another month or so.)

Any help, suggestions or advice on what settings to use to maximise security and minimise time to run would be much appreciated. Thank you.
 
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