Estimated time for Erasing

Myfamilyguy76

New Member
What is the estimated time for erasing unused space on a 140 GB drive and using the Guttman technique :?:
 

jackjack

Member
It's hard to answer, It depends on how much free space versus used space there is on the 140Gb drive and even then you're not gonna really know until you try.

Example 250Gig drive with 36Gig free free space wipe (no cluster tips)

35 pass = 850min
7 pass = 170min
3 pass = 75 min
pseudo pass = 26 min
Schneier 7 pass = 167 min
null pass = 24min

These are just rough figures based on the initial remaining time given by eraser when running the wipes, they may drop or rise as the wipe progresses.

35 pass is considered overkill these days, it was only recommended on drives years ago (pre 2000). You would be better off with 3 pass (have a read of this )
 

spy1

Member
I have a 160GB HD on my computer here. Since I have absolutely no use whatsoever for that much HD space, I took the freeware program TrueCrypt and created a file container the size of which only left me with slightly under 21GB of freespace. (See screenshot). Eraser doesn't "see" any freespace in the encrypted container if it's not mounted when a freespace wipe is run on "C:" drive, so it skips over it quickly. (The container itself can be freespace-wiped by Eraser, but only if the container is mounted at the time).

Seemed to speed up the erasing process, for sure. Pete
 

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spy1

Member
"When a file does not fill up the last cluster (group of sectors) it is using, an incomplete sector is filled in with a bit of what is in RAM, so this part is called RAM slack. The rest of the unused sectors in the cluster are called drive slack, since any info in them is what was written on the drive previously. The combination of the RAM slack and drive slack are called file slack (since it is contiguous unused area, but still associated with the file).

"File slack" and "cluster tip" are the same thing, referring to the unused portion of the incomplete cluster." - Gralfus

Also see: http://www.forensics-intl.com/def6.html

http://www.niiconsulting.com/checkmate/ ... ive-slack/
 

jackjack

Member
Good lordy, what part of "It depends on how much free space versus used space there is" was not clear.

If you really want to know how long it will take for your hard drive, start a free space wipe (with out cluster tip erasing as that doesnt give an estimate) wait a few seconds and it will tell you how long it is estimated to take. Once you know how long it will roughly take you can cancel the wipe. (Make sure you turn on cluster tip erasing when you go to actually run the wipe)

If you can't do that but still want to know how long it will take, I'll happily give you a PO Box to ship your hard drive to...
 

spy1

Member
A single pseudorandom pass is sufficient for all purposes other than evading examination by three-letter government agencies, so I don't understand why your emphasis is on the 35-pass Gutmann wipe.

And if it is that sensitive, then quit worrying about how long it will take and just do it. Pete
 

gobananasnet

New Member
1-1/2 DAYS [you read that correctly "DAYS"] and it's only about 55% complete. USB 2.0 External 1-TB drive being cleared. Default settings used. Does this sound right? Is there a better way?

Also I did an USB 2.0 External 100-GB drive three times and it kept coming back "Completed with Errors". No explanation what the errors were.

Crazy making for sure.

Additionally, I want to make sure the drives are clean when finished. I work in the medical industy in Los Angeles / Hollywood, and have some patient data on these drives that I'm required to keep private U.S. "HIPAA Laws". And several of the patients are celebrities, so I want to be certain their info is not recoverable.

Thanks in advance for your help!
 

DavidHB

Active Member
The errors will be in the log. If you don't know where that is, read the FAQ post called "Getting to know Eraser 6". If you are using Eraser 6.0.x, it might be flagging up errors that aren't in practice errors at all (Joel has changed the categorisation a bit in the development version).

Erase time is a function primarily of the amount of free space being erased, drive (that is drive plus interface) speed and the number of passes. For erasing free space, use a single pass method. Al;so, disable antivirus and other background programs to reduce the number of disk accesses during a free space erase.

Without knowing more details of your setup, it is difficult to be precise about why the erase is taking so long. On my desktop machines, I would expect a 1TB erase (single pase) to take hours rather than days.

David
 

Joel

Active Member
Based on simple arithmetic, a 1TB drive should take around 10 hours to erase over USB 2.0. If you happened to do a Gutmann erase, then that would take 350 hours, i.e. about 2 weeks.
 
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