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What is the accelerate method of free space wiping with random fill?

How to know the progress of sfill free space wiping process?Why does the total space used on my hard drive not reflect what Disk Usage Analyzer Says?Meaning of the free space indication in DelugePartitioning with Windows 7, no free spaceAfter uninstalling wine some of the free space is 'locked'?How does the automatic installation work with free space?What is the safest method for repartitioning space from the / partition?No more disk space: How can I find what is taking up the space?How to know the progress of sfill free space wiping process?Wiping free disk space by deleting large amount of files regularly?Free space in my laptop with Ubuntu 18.04 preinstalled

1

I am currently using sfill to wipe free space in my root partition ( /dev/sdaX). Its default setting is a 38 pass sudo sfill -v / but its taking hours to complete this step. I then tried to use less secure three pass method sudo sfill -lv / the problem is its taking fairly the same amount of time to wipe free space as the default. It is due to dev/urandom which peaks at 13MB/s. While searching for an alterntive method to speed up free space wiping step, I reached this link which uses openssl to randomize the wipe.

 openssl rand $(</proc/partitions awk '$4=="sda" {print $3*1024}') >/dev/sda

Is this a good way to wipe free space in root drive or other safer method exists? In the above command sda is our root partion sdaX, right?

security disk-usage openssl storage secure-erase

share|improve this question

edited 6 mins ago

Pablo Bianchi

2,94521535

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  On my machine dd if=/dev/urandom bs=1M count=1000 | pv >/dev/null shows that /dev/urandom runs at least at 170MB/s (about 5 seconds/GB). dd if=/dev/urandom bs=1M of=/somebigfile is about as fast as you can get.
  
  – xenoid
  Apr 14 '18 at 7:01
  
  
  

  
  
  
  

add a comment | 

1

I am currently using sfill to wipe free space in my root partition ( /dev/sdaX). Its default setting is a 38 pass sudo sfill -v / but its taking hours to complete this step. I then tried to use less secure three pass method sudo sfill -lv / the problem is its taking fairly the same amount of time to wipe free space as the default. It is due to dev/urandom which peaks at 13MB/s. While searching for an alterntive method to speed up free space wiping step, I reached this link which uses openssl to randomize the wipe.

 openssl rand $(</proc/partitions awk '$4=="sda" {print $3*1024}') >/dev/sda

Is this a good way to wipe free space in root drive or other safer method exists? In the above command sda is our root partion sdaX, right?

security disk-usage openssl storage secure-erase

share|improve this question

edited 6 mins ago

Pablo Bianchi

2,94521535

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  On my machine dd if=/dev/urandom bs=1M count=1000 | pv >/dev/null shows that /dev/urandom runs at least at 170MB/s (about 5 seconds/GB). dd if=/dev/urandom bs=1M of=/somebigfile is about as fast as you can get.
  
  – xenoid
  Apr 14 '18 at 7:01
  
  
  

  
  
  
  

add a comment | 

I am currently using sfill to wipe free space in my root partition ( /dev/sdaX). Its default setting is a 38 pass sudo sfill -v / but its taking hours to complete this step. I then tried to use less secure three pass method sudo sfill -lv / the problem is its taking fairly the same amount of time to wipe free space as the default. It is due to dev/urandom which peaks at 13MB/s. While searching for an alterntive method to speed up free space wiping step, I reached this link which uses openssl to randomize the wipe.

 openssl rand $(</proc/partitions awk '$4=="sda" {print $3*1024}') >/dev/sda

Is this a good way to wipe free space in root drive or other safer method exists? In the above command sda is our root partion sdaX, right?

security disk-usage openssl storage secure-erase

share|improve this question

edited 6 mins ago

Pablo Bianchi

2,94521535

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

 openssl rand $(</proc/partitions awk '$4=="sda" {print $3*1024}') >/dev/sda

share|improve this question

edited 6 mins ago

Pablo Bianchi

2,94521535

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

share|improve this question

edited 6 mins ago

Pablo Bianchi

2,94521535

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

edited 6 mins ago

Pablo Bianchi

2,94521535

edited 6 mins ago

Pablo Bianchi

2,94521535

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

asked Apr 14 '18 at 5:42

EkaEka

1,05862139

1 Answer
1

active

oldest

votes

1

First and foremost, wiping your drive 35+ times is completely unnecessary. The Guttmann Method (35 wipes) is something designed to wipe any drive, from brand-new modern spinning drives to massive ancient 5MB behemoths that are more likely to store resident data. With that said, wiping your drive once or twice is pretty much the best you can do. You have a modern magnetic drive.

The sfill command is... silly. See the manpage for what I mean. If you only need to wipe the drive out with zeros, you can just use the (far simpler) sfill -llz / to wipe out all free space with zeros, once. This (according to Guttmann himself, see above link as well as right here) is more than good enough for the vast majority of systems. As you're writing zeros instead of random data, your only speed limit will be your drive's speed.

If you need plausible deniability ("No, officer, I didn't wipe this hard drive"), you can use the sister command sfill -ll / to wipe your drive in a single pass with random data. This will be slower, but just as secure for your system as any other wiping method with the addition of possible plausible deniability.

However, if you really need to ensure that no data is absolutely recoverable from this drive (in theory or otherwise), use a drill.

share|improve this answer

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136

add a comment | 

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1

First and foremost, wiping your drive 35+ times is completely unnecessary. The Guttmann Method (35 wipes) is something designed to wipe any drive, from brand-new modern spinning drives to massive ancient 5MB behemoths that are more likely to store resident data. With that said, wiping your drive once or twice is pretty much the best you can do. You have a modern magnetic drive.

The sfill command is... silly. See the manpage for what I mean. If you only need to wipe the drive out with zeros, you can just use the (far simpler) sfill -llz / to wipe out all free space with zeros, once. This (according to Guttmann himself, see above link as well as right here) is more than good enough for the vast majority of systems. As you're writing zeros instead of random data, your only speed limit will be your drive's speed.

If you need plausible deniability ("No, officer, I didn't wipe this hard drive"), you can use the sister command sfill -ll / to wipe your drive in a single pass with random data. This will be slower, but just as secure for your system as any other wiping method with the addition of possible plausible deniability.

However, if you really need to ensure that no data is absolutely recoverable from this drive (in theory or otherwise), use a drill.

share|improve this answer

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136

add a comment | 

1

First and foremost, wiping your drive 35+ times is completely unnecessary. The Guttmann Method (35 wipes) is something designed to wipe any drive, from brand-new modern spinning drives to massive ancient 5MB behemoths that are more likely to store resident data. With that said, wiping your drive once or twice is pretty much the best you can do. You have a modern magnetic drive.

The sfill command is... silly. See the manpage for what I mean. If you only need to wipe the drive out with zeros, you can just use the (far simpler) sfill -llz / to wipe out all free space with zeros, once. This (according to Guttmann himself, see above link as well as right here) is more than good enough for the vast majority of systems. As you're writing zeros instead of random data, your only speed limit will be your drive's speed.

If you need plausible deniability ("No, officer, I didn't wipe this hard drive"), you can use the sister command sfill -ll / to wipe your drive in a single pass with random data. This will be slower, but just as secure for your system as any other wiping method with the addition of possible plausible deniability.

However, if you really need to ensure that no data is absolutely recoverable from this drive (in theory or otherwise), use a drill.

share|improve this answer

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136

add a comment | 

First and foremost, wiping your drive 35+ times is completely unnecessary. The Guttmann Method (35 wipes) is something designed to wipe any drive, from brand-new modern spinning drives to massive ancient 5MB behemoths that are more likely to store resident data. With that said, wiping your drive once or twice is pretty much the best you can do. You have a modern magnetic drive.

The sfill command is... silly. See the manpage for what I mean. If you only need to wipe the drive out with zeros, you can just use the (far simpler) sfill -llz / to wipe out all free space with zeros, once. This (according to Guttmann himself, see above link as well as right here) is more than good enough for the vast majority of systems. As you're writing zeros instead of random data, your only speed limit will be your drive's speed.

If you need plausible deniability ("No, officer, I didn't wipe this hard drive"), you can use the sister command sfill -ll / to wipe your drive in a single pass with random data. This will be slower, but just as secure for your system as any other wiping method with the addition of possible plausible deniability.

However, if you really need to ensure that no data is absolutely recoverable from this drive (in theory or otherwise), use a drill.

share|improve this answer

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136

share|improve this answer

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136

answered Aug 31 '18 at 15:50

Kaz WolfeKaz Wolfe

26.1k1376136