Secure Erase and Validation

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The secure erase function wipes out data on the disk per the US Department of Defense standard DoD 5220.22-M specification.  (Note, the specification requires three full triple-pass iterations for DoD compliance). This function is reserved for SCSI, SAS, SSA, and Fibre Channel disks only.

 

SMARTMon-UX has several commands relating to secure erase:

-securecheckall        Scans the entire disk, and reports the count and standard deviation for all 256 possible byte values on the

                       entire disk.

-securecheck n        This performs the action in the same way as -securecheck, but it will automatically terminate after either

                       a user-specified amount of time, or after it determines that the data is not random, whichever comes first.

 

-secure                This is the function that implements the secure erase.

 

 

 

Syntax for Secure Erase

smartmon-ux -secure nFullCycles devicename

 

where n is a decimal number from 1-3 which corresponds to the number of full write cycles.

 

Additional Information

Each cycle corresponds to three full passes where data is written to every addressable block.  The first cycle sets every bit to one, the second sets every bit to zero. The final pass in each cycle writes random data.  This process can take hours or days to complete, and if you want to insure that your old data is destroyed beyond all ability to recover it, then you should pulverize the disk drive into pieces no larger than a few square millimeters.

 

Our code takes advantage of specialized commands found in some disk drives to write a pattern to a large number of blocks quickly and efficiently.  If your disk drive supports this command, then you will notice that the cycles that set and clear each bit run several times faster than a cycle that randomizes data.

 

Example

C:\scratch>smartmonux-ux -secure 2 \\.\SCSI4Port4Path0Target1Lun0

SMARTMonUX [Release 1.32, Build  12-JAN-2007] - Copyright 2001-2006 SANtools, Inc. http://www.SANtools.com

Discovered IBM DNEF-309170 S/N "AE1J3393" on \\.\SCSI4Port4Path0Target1Lun0 [SES] (Not Enabling SMART) [Bus/Port/ID.LUN=0/4/1.0](8748 MB)

 

****************************************************************************************

* Warning:  You have initiated the secure erase function. No checks will be made to    *

*           verify that the disk(s) aren't mounted or in use in any way.               *

*                                                                                      *

*           This will destroy all data on the disk,  and can take hours or possibly    *

*           days to complete.  If you run this test on  a logical disk (i.e, RAID),    *

*           then some data will remain on the disks (metadata & parity data).  If      *

*           the disks are behind a RAID controller then you will need to run this      *

*           software on the individual disk drives.                                    *

*                                                                                      *

*           If you have provided a list of drives to erase, then additional disks will *

*           be erased, one at a time as the process completes for a disk.              *

*                                                                                      *

*           You may specify the total number of passes that will be done. After an     *

*           initial format to clear out data that might be in usable, but formerly     *

*           reallocated sectors, then the software will perform your specified number  *

*           of cycles. Each cycle consists of 3 full write passes.  The first pass     *

*           zeros every bit, then every bit is set to a one.  The third write cycle    *

*           writes random data to the entire disk.                                     *

****************************************************************************************

 

Are you sure you want to erase the IBM DNEF-309170 disk at \\.\SCSI4Port4Path0Target1Lun0? Answer "YES" to begin: YES

 

The US DoD standard for secure erase  specifies 3 iterations (each iteration is 3 passes).  A single

iteration is sufficient to prevent data recovery without forensic recovery equipment, and most users

therefore specify a single iteration.  How many iterations do you wish to perform? (2)): 2

 

Beginning secure erase where 6 full passes (2 iterations) will be invoked.

Pass #   1: Setting every bit to 0 ...  (Pass time:     9.5m, Total:    9.5m)

Pass #   2: Setting every bit to 1 ...  (Pass time:     9.5m, Total:   19.0m)

Pass #   3: Randomizing every bit ...   (Pass time:    29.6m, Total:   47.6m)

Pass #   4: Setting every bit to 0 ...  (Pass time:     9.5m, Total:   57.1m)

Pass #   5: Setting every bit to 1 ...  (Pass time:     9.5m, Total:   66.6m)

Pass #   6: Randomizing every bit ...   (Pass time:    29.6m, Total:   96.2m)

 

C:\scratch>

 

(Note: Due to the improved secure erase logic introduced in 1.35, the same disk drive reported the times below. The randomization phases run over twice as fast)

Pass #   1: Setting every bit to 0 ...     (Pass time:    9.5m, Total:    9.5m)

Pass #   2: Setting every bit to 1 ...     (Pass time:    9.5m, Total:   18.9m)

Pass #   3: Randomizing every bit ...      (Pass time:   9.8m, Total:   28.7m)

Pass #   4: Setting every bit to 0 ...     (Pass time:    9.5m, Total:   38.2m)

Pass #   5: Setting every bit to 1 ...     (Pass time:    9.5m, Total:   47.6m)

Pass #   6: Randomizing every bit ...      (Pass time:   9.7m, Total:   57.3m)

 

 

Disclaimer

Use this feature at your own risk. SANtools will not guarantee that the secure erase will prevent your data from being recoverable.  It is the responsibility of the user to insure that the process completes, and that the appropriate device was selected.  If you select logical partitions, LUNs on RAID controllers, or logical disks, then this will not destroy any metadata or redundant data.

 

In addition, if your disk drives were short stroked (i.e., they present a usable capacity that is smaller then the actual physical capacity to the operating system, then not all of the disk will get erased.   If you have any doubts as to whether or not the usable capacity is same as physical capacity, then invoke the command -capacity 0 first.  This will resize the disk to the maximum capacity.

 

Syntax for Secure Check

smartmon-ux -securecheck n devicename

 

where n is a decimal number from 1-3 which corresponds to the number of full write cycles.

 

Additional Information

Each cycle corresponds to three full passes where data is written to every addressable block.  The first cycle sets every bit to one, the second sets every bit to zero. The final pass in each cycle writes random data.  This process can take hours or days to complete, and if you want to insure that your old data is destroyed beyond all ability to recover it, then you should pulverize the disk drive into pieces no larger than a few square millimeters.

 

Our code takes advantage of specialized commands found in some disk drives to write a pattern to a large number of blocks quickly and efficiently.  If your disk drive supports this command, then you will notice that the cycles that set and clear each bit run several times faster than a cycle that randomizes data.

 

Example

[root@ia64linux smartmon]# ./smartmon-ux -securecheck 1 /dev/sg9

SMARTMon-UX [Release 1.35, Build 18-JAN-2008] - Copyright 2001-2008 SANtools(R), Inc. http://www.SANtools.com

Discovered IBM DNEF-309170 S/N "AJ1P8115" on Device /dev/sg9 (Adapter.Ch/ID.LUN=2.0/7.0) [SES] (Not Enabling SMART)(8748 MB)

 

Beginning SANtools secure erase verification test for IBM DNEF-309170 ...

Test completed.

 

Report summary:

IO errors for IBM DNEF-309170 at /dev/sg9: No problems found.

Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount

  0  96.460        15804     1   0.079           13     2   0.031            5     3   0.000            0

  4   0.018            3     5   0.031            5     6   0.024            4     7   0.067           11

  8   0.031            5     9   0.006            1     A   0.018            3     B   0.031            5

  C   0.006            1     D   0.000            0     E   0.012            2     F   0.000            0

 10   0.043            7    11   0.031            5    12   0.000            0    13   0.043            7

 14   0.000            0    15   0.000            0    16   0.000            0    17   0.000            0

 18   0.006            1    19   0.018            3    1A   0.000            0    1B   0.012            2

 1C   0.006            1    1D   0.000            0    1E   0.006            1    1F   0.006            1

 20   0.043            7    21   0.006            1    22   0.000            0    23   0.012            2

 24   0.006            1    25   0.006            1    26   0.000            0    27   0.000            0

 28   0.000            0    29   0.000            0    2A   0.006            1    2B   0.006            1

 2C   0.012            2    2D   0.073           12    2E   0.000            0    2F   0.000            0

 30   0.067           11    31   0.043            7    32   0.049            8    33   0.018            3

 34   0.049            8    35   0.018            3    36   0.049            8    37   0.067           11

 38   0.031            5    39   0.043            7    3A   0.000            0    3B   0.000            0

 3C   0.006            1    3D   0.000            0    3E   0.012            2    3F   0.018            3

 40   0.006            1    41   0.012            2    42   0.018            3    43   0.006            1

 44   0.018            3    45   0.012            2    46   0.031            5    47   0.000            0

 48   0.006            1    49   0.018            3    4A   0.000            0    4B   0.006            1

 4C   0.000            0    4D   0.012            2    4E   0.037            6    4F   0.012            2

 50   0.031            5    51   0.006            1    52   0.018            3    53   0.000            0

 54   0.000            0    55   0.024            4    56   0.049            8    57   0.012            2

 58   0.000            0    59   0.006            1    5A   0.018            3    5B   0.000            0

 5C   0.012            2    5D   0.000            0    5E   0.000            0    5F   0.000            0

 60   0.018            3    61   0.116           19    62   0.049            8    63   0.043            7

 64   0.067           11    65   0.085           14    66   0.012            2    67   0.031            5

 68   0.012            2    69   0.079           13    6A   0.031            5    6B   0.012            2

 6C   0.018            3    6D   0.012            2    6E   0.067           11    6F   0.043            7

 70   0.031            5    71   0.006            1    72   0.079           13    73   0.073           12

 74   0.104           17    75   0.018            3    76   0.024            4    77   0.006            1

 78   0.000            0    79   0.012            2    7A   0.000            0    7B   0.000            0

 7C   0.031            5    7D   0.006            1    7E   0.018            3    7F   0.000            0

 80   0.037            6    81   0.012            2    82   0.000            0    83   0.024            4

 84   0.000            0    85   0.000            0    86   0.006            1    87   0.000            0

 88   0.006            1    89   0.000            0    8A   0.043            7    8B   0.049            8

 8C   0.000            0    8D   0.000            0    8E   0.006            1    8F   0.000            0

 90   0.000            0    91   0.000            0    92   0.000            0    93   0.000            0

 94   0.000            0    95   0.006            1    96   0.000            0    97   0.000            0

 98   0.006            1    99   0.000            0    9A   0.000            0    9B   0.000            0

 9C   0.000            0    9D   0.000            0    9E   0.000            0    9F   0.000            0

 A0   0.024            4    A1   0.000            0    A2   0.000            0    A3   0.000            0

 A4   0.006            1    A5   0.000            0    A6   0.000            0    A7   0.000            0

 A8   0.000            0    A9   0.006            1    AA   0.024            4    AB   0.000            0

 AC   0.006            1    AD   0.000            0    AE   0.000            0    AF   0.000            0

 B0   0.000            0    B1   0.012            2    B2   0.000            0    B3   0.000            0

 B4   0.031            5    B5   0.006            1    B6   0.012            2    B7   0.006            1

 B8   0.006            1    B9   0.006            1    BA   0.000            0    BB   0.018            3

 BC   0.012            2    BD   0.031            5    BE   0.012            2    BF   0.012            2

 C0   0.006            1    C1   0.012            2    C2   0.000            0    C3   0.006            1

 C4   0.000            0    C5   0.006            1    C6   0.006            1    C7   0.012            2

 C8   0.012            2    C9   0.006            1    CA   0.000            0    CB   0.012            2

 CC   0.000            0    CD   0.049            8    CE   0.000            0    CF   0.000            0

 D0   0.006            1    D1   0.006            1    D2   0.012            2    D3   0.000            0

 D4   0.000            0    D5   0.000            0    D6   0.012            2    D7   0.000            0

 D8   0.000            0    D9   0.012            2    DA   0.000            0    DB   0.000            0

 DC   0.012            2    DD   0.000            0    DE   0.006            1    DF   0.000            0

 E0   0.006            1    E1   0.000            0    E2   0.012            2    E3   0.006            1

 E4   0.018            3    E5   0.006            1    E6   0.000            0    E7   0.000            0

 E8   0.012            2    E9   0.000            0    EA   0.006            1    EB   0.031            5

 EC   0.000            0    ED   0.000            0    EE   0.006            1    EF   0.000            0

 F0   0.006            1    F1   0.006            1    F2   0.006            1    F3   0.006            1 

 

The -securecheckall command reported the byte distribution in this manner for the drive.

           

Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount

 0  90.269   8280514948     1   0.030      2719293     2   0.044      4074225     3   0.044      4073945

 4   0.015      1358881     5   0.030      2716384     6   0.015      1358167     7   0.030      2715616

 8   0.000          868     9   0.030      2715410     A   0.015      1358393     B   0.074      6787828

 C   0.030      2715676     D   0.030      2715813     E   0.074      6787691     F   0.015      1358379

10   0.000         1203    11   0.000          605    12   0.000         1164    13   0.015      1358258

14   0.030      2715650    15   0.015      1358104    16   0.030      2715541    17   0.030      2715050

18   0.000         1278    19   0.074      6788284    1A   0.015      1357602    1B   0.015      1357852

1C   0.044      4072937    1D   0.015      1357721    1E   0.015      1357906    1F   0.030      2715290

20   0.030      2716092    21   0.015      1357644    22   0.044      4072813    23   0.015      1357984

24   0.015      1357950    25   0.015      1357723    26   0.044      4072723    27   0.059      5430210

28   0.000          570    29   0.089      8145178    2A   0.074      6788119    2B   0.030      2715277

2C   0.015      1357971    2D   0.015      1358034    2E   0.059      5429833    2F   0.015      1357848

30   0.044      4073540    31   0.044      4072713    32   0.044      4072990    33   0.015      1358020

34   0.030      2716029    35   0.044      4072693    36   0.059      5430486    37   0.030      2715315

38   0.015      1358122    39   0.015      1358274    3A   0.015      1357727    3B   0.000          784

3C   0.030      2715393    3D   0.015      1358092    3E   0.030      2715660    3F   0.074      6787645

40   0.015      1358068    41   0.000          718    42   0.059      5436035    43   0.044      4073760

44   0.030      2715039    45   0.044      4072566    46   0.030      2715276    47   0.059      5430101

48   0.044      4073455    49   0.030      2715177    4A   0.030      2716231    4B   0.074      6793306

4C   0.030      2721185    4D   0.030      2715280    4E   0.059      5430253    4F   0.030      2715290

50   0.030      2715517    51   0.030      2715034    52   0.059      5430016    53   0.000          326

54   0.030      2715149    55   0.059      5430566    56   0.015      1363791    57   0.030      2715255

58   0.000          811    59   0.015      1357994    5A   2.172    199228412    5B   0.000          301

5C   0.030      2715130    5D   0.015      1357961    5E   0.104      9502348    5F   0.030      2715298

60   0.015      1357801    61   0.044      4072755    62   0.015      1357748    63   0.000          249

64   0.030      2715323    65   0.015      1357799    66   0.059      5431198    67   0.030      2715080

68   0.030      2715396    69   0.059      5429874    6A   0.000          429    6B   0.030      2715268

6C   0.030      2715037    6D   0.015      1357720    6E   0.044      4072687    6F   0.044      4072582

70   0.030      2715555    71   0.000          311    72   0.015      1358155    73   0.015      1357888

74   0.030      2715167    75   0.030      2715141    76   0.044      4073174    77   0.030      2715669

78   0.030      2715015    79   0.015      1357848    7A   0.030      2715250    7B   0.030      2715120

7C   0.030      2715692    7D   0.074      6787384    7E   0.000          425    7F   0.044      4072928

80   0.059      5430892    81   0.030      2715263    82   0.015      1358505    83   0.074      6787875

84   0.015      1358134    85   0.030      2715573    86   0.030      2715386    87   0.000          676

88   0.030      2715552    89   0.015      1358286    8A   0.015      1358115    8B   0.015      1358216

8C   0.030      2715387    8D   0.059      5430223    8E   0.015      1357855    8F   0.059      5430347

90   0.015      1358283    91   0.030      2715634    92   0.015      1357964    93   0.000          677

94   0.030      2715506    95   0.030      2715254    96   0.000          927    97   0.030      2715509

98   0.000          681    99   0.089      8145415    9A   0.015      1357962    9B   0.030      2715512

9C   0.000          424    9D   0.015      1357967    9E   0.030      2715632    9F   0.015      1358167

A0   0.030      2715529    A1   0.030      2716253    A2   0.044      4072789    A3   0.015      1358111

A4   0.015      1357834    A5   0.000          806    A6   0.044      4072873    A7   0.030      2715252

A8   0.030      2715509    A9   0.030      2715376    AA   0.044      4073192    AB   0.015      1358090

AC   0.015      1357850    AD   0.015      1358341    AE   0.000          675    AF   0.030      2715508

B0   0.030      2715516    B1   0.044      4073173    B2   0.030      2715505    B3   0.015      1358105

B4   0.015      1358494    B5   0.059      5430338    B6   0.000          699    B7   0.059      5430480

B8   0.030      2715782    B9   0.015      1358105    BA   0.000          810    BB   0.000          690

BC   0.030      2715644    BD   0.030      2715779    BE   0.044      4072674    BF   0.044      4072798

C0   0.044      4073371    C1   0.074      6787786    C2   0.059      5430217    C3   0.044      4072980

C4   0.030      2715254    C5   0.015      1357964    C6   0.030      2715388    C7   0.015      1358696

C8   0.030      2715620    C9   0.030      2715778    CA   0.030      2715638    CB   0.059      5430345

CC   0.044      4072792    CD   0.015      1358239    CE   0.030      2715635    CF   0.000          802

D0   0.030      2715400    D1   0.000          932    D2   0.044      4072812    D3   0.044      4072795

D4   0.030      2715506    D5   0.030      2715884    D6   0.059      5430847    D7   0.044      4072670

D8   0.044      4073186    D9   0.030      2715646    DA   0.015      1357971    DB   0.030      2715383

DC   0.044      4072798    DD   0.044      4073048    DE   0.000          550    DF   0.015      1358095

E0   0.030      2715540    E1   0.030      2715485    E2   0.015      1357987    E3   0.059      5430484

E4   0.030      2715398    E5   0.000          566    E6   0.044      4073310    E7   0.015      1357841

E8   0.000          745    E9   0.030      2715515    EA   0.030      2715386    EB   0.015      1358124

EC   0.044      4072794    ED   0.044      4072660    EE   0.015      1357837    EF   0.044      4072670

F0   0.044      4072834    F1   0.015      1358477    F2   0.059      5430340    F3   0.044      4072951

F4   0.030      2716624    F5   0.059      5430217    F6   0.015      1358097    F7   0.030      2715287

F8   0.030      2715542    F9   0.000          596    FA   0.059      5430431    FB   0.030      2715398

FC   0.059      5430479    FD   0.015      1358236    FE   0.000          710    FF   0.128     11751181

 

Total bytes analyzed above: 9173114880; on device: 9173114880

Note: The longest consecutive sequence is 38102016 bytes long, and standard deviation is  5.630.

** THIS DISK DOES NOT CONTAIN RANDOM DATA ***

[root@ia64linux smartmon]#

 

 

This disk must have valid data on it. Notice the large number of zeros and higher percentages of digits 0-9.  We run a single-pass secure erase, and then report the results.

 

[root@ia64linux smartmon]# ./smartmon-ux -secure 1 /dev/sg9

SMARTMon-UX [Release 1.35, Build 21-JAN-2008] - Copyright 2001-2008 SANtools(R), Inc. http://www.SANtools.com

Discovered IBM DNEF-309170 S/N "AJ1P8115" on Device /dev/sg9 (Adapter.Ch/ID.LUN=2.0/7.0) [SES] (SMART enabled)(8748 MB)

 

****************************************************************************************

* Warning:  You have initiated the secure erase function. No checks will be made to    *

*           verify that the disk(s) aren't mounted or in use in any way.               *

*                                                                                      *

*           This will destroy all data on the disk,  and can take hours or possibly    *

*           days to complete.  If you run this test on  a logical disk (i.e, RAID),    *

*           then some data will remain on the disks (metadata & parity data).  If      *

*           the disks are behind a RAID controller then you will need to run this      *

*           software on the individual disk drives.                                    *

*                                                                                      *

*           If you have provided a list of drives to erase, then additional disks will *

*           be erased, one at a time as the process completes for a disk.              *

*                                                                                      *

*           You may specify the total number of passes that will be done. After an     *

*           initial format to clear out data that might be in usable, but formerly     *

*           reallocated sectors, then the software will perform your specified number  *

*           of cycles. Each cycle consists of 3 full write passes.  The first pass     *

*           zeros every bit, then every bit is set to a one.  The third write cycle    *

*           writes random data to the entire disk.                                     *

****************************************************************************************

 

Are you sure you want to erase the IBM DNEF-309170 disk at /dev/sg9? Answer "YES" to begin: YES

 

The US DoD standard for secure erase  specifies 3 iterations (each iteration is 3 passes).  A single

iteration is sufficient to prevent data recovery without forensic recovery equipment, and most users

therefore specify a single iteration.  How many iterations do you wish to perform? (1)): 1

 

Beginning secure erase where 3 full passes (1 iteration) will be invoked.

Pass #   1: Setting every bit to 0 ...     (Pass time:    9.5m, Total:    9.5m)

Pass #   2: Setting every bit to 1 ...     (Pass time:    9.5m, Total:   18.9m)

Pass #   3: Randomizing every bit ...      (Pass time:   11.5m, Total:   30.4m)

The device has successfully been erased.

 

O errors for IBM DNEF-309170 at /dev/sg9: No problems found.

Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  

 0   0.391     35829972     1   0.391     35833545     2   0.391     35828841     3   0.391     35831614

 4   0.391     35828018     5   0.391     35845415     6   0.391     35827569     7   0.391     35842468

 8   0.391     35829414     9   0.391     35832505     A   0.391     35832274     B   0.391     35829931

 C   0.391     35830439     D   0.391     35834870     E   0.391     35839300     F   0.390     35819188

10   0.391     35841614    11   0.391     35829669    12   0.391     35829391    13   0.390     35816735

14   0.391     35832689    15   0.391     35830727    16   0.391     35825645    17   0.391     35830039

18   0.391     35836274    19   0.391     35821265    1A   0.391     35830096    1B   0.391     35822488

1C   0.390     35819790    1D   0.391     35834652    1E   0.391     35828673    1F   0.391     35828992

20   0.391     35825176    21   0.391     35831327    22   0.391     35830549    23   0.391     35836446

24   0.391     35827115    25   0.391     35828167    26   0.391     35836304    27   0.391     35842787

28   0.391     35834765    29   0.391     35835998    2A   0.391     35834606    2B   0.391     35824023

2C   0.391     35825272    2D   0.391     35835496    2E   0.391     35836011    2F   0.390     35811043

30   0.391     35834105    31   0.391     35837830    32   0.391     35835902    33   0.391     35823527

34   0.391     35834823    35   0.391     35829004    36   0.391     35836238    37   0.391     35831478

38   0.391     35839152    39   0.391     35833580    3A   0.391     35834182    3B   0.391     35835355

3C   0.391     35828933    3D   0.391     35840625    3E   0.391     35839028    3F   0.391     35836238

40   0.391     35833824    41   0.391     35840651    42   0.391     35827843    43   0.391     35823703

44   0.391     35825350    45   0.391     35825704    46   0.391     35826986    47   0.391     35826579

48   0.391     35824667    49   0.391     35825018    4A   0.391     35826353    4B   0.391     35832409

4C   0.391     35831285    4D   0.391     35833121    4E   0.391     35833779    4F   0.391     35834653

50   0.391     35826422    51   0.391     35829101    52   0.391     35831170    53   0.391     35839404

54   0.391     35834025    55   0.391     35836547    56   0.391     35839656    57   0.391     35834219

58   0.391     35838322    59   0.391     35842217    5A   0.391     35832608    5B   0.391     35830795

5C   0.391     35830398    5D   0.391     35841648    5E   0.391     35828385    5F   0.391     35843732

60   0.391     35829973    61   0.391     35840043    62   0.391     35834767    63   0.390     35816302

64   0.391     35837421    65   0.391     35828803    66   0.391     35838699    67   0.391     35834395

68   0.391     35829298    69   0.391     35830615    6A   0.391     35835097    6B   0.391     35829154

6C   0.391     35824419    6D   0.391     35831141    6E   0.391     35822070    6F   0.391     35834263

70   0.391     35827148    71   0.391     35837694    72   0.391     35827658    73   0.391     35837475

74   0.391     35828163    75   0.391     35838447    76   0.391     35835951    77   0.390     35817271

78   0.391     35825778    79   0.391     35829808    7A   0.391     35837156    7B   0.391     35834523

7C   0.391     35824324    7D   0.391     35833073    7E   0.391     35830341    7F   0.391     35831459

80   0.391     35842876    81   0.391     35831559    82   0.391     35834054    83   0.391     35832884

84   0.391     35839239    85   0.391     35830311    86   0.391     35827406    87   0.391     35825002

88   0.391     35833267    89   0.391     35828105    8A   0.391     35841893    8B   0.391     35839614

8C   0.391     35824686    8D   0.391     35833548    8E   0.391     35834591    8F   0.391     35839205

90   0.391     35831866    91   0.391     35841088    92   0.391     35846651    93   0.391     35833396

94   0.391     35834672    95   0.391     35835735    96   0.391     35826951    97   0.391     35839477

98   0.391     35831369    99   0.391     35837716    9A   0.391     35831697    9B   0.391     35840650

9C   0.391     35835059    9D   0.391     35826102    9E   0.391     35830481    9F   0.391     35835666

A0   0.391     35825973    A1   0.391     35828942    A2   0.391     35832435    A3   0.391     35828621

A4   0.391     35834144    A5   0.391     35831601    A6   0.391     35828446    A7   0.391     35843438

A8   0.391     35829797    A9   0.391     35824495    AA   0.391     35831540    AB   0.391     35834889

AC   0.391     35832530    AD   0.391     35833245    AE   0.391     35835582    AF   0.391     35830982

B0   0.391     35840199    B1   0.391     35830083    B2   0.391     35832403    B3   0.391     35833307

B4   0.391     35827928    B5   0.391     35843003    B6   0.391     35835190    B7   0.391     35837419

B8   0.391     35824222    B9   0.391     35826359    BA   0.391     35836523    BB   0.391     35834894

BC   0.391     35827413    BD   0.391     35833474    BE   0.391     35839098    BF   0.391     35834938

C0   0.391     35835834    C1   0.391     35842455    C2   0.391     35831998    C3   0.391     35833223

C4   0.391     35821668    C5   0.391     35836508    C6   0.391     35829402    C7   0.391     35829226

C8   0.391     35838460    C9   0.391     35823475    CA   0.391     35845628    CB   0.391     35837043

CC   0.391     35831381    CD   0.391     35831882    CE   0.391     35835077    CF   0.391     35832947

D0   0.391     35837892    D1   0.391     35829781    D2   0.391     35836569    D3   0.391     35841382

D4   0.391     35828180    D5   0.391     35821680    D6   0.391     35824102    D7   0.391     35844498

D8   0.391     35827409    D9   0.391     35828268    DA   0.391     35840052    DB   0.391     35841451

DC   0.391     35830459    DD   0.391     35835154    DE   0.391     35837332    DF   0.391     35830882

E0   0.391     35828163    E1   0.391     35835412    E2   0.391     35836631    E3   0.391     35835514

E4   0.391     35828177    E5   0.391     35833115    E6   0.391     35828199    E7   0.391     35830728

E8   0.391     35836584    E9   0.391     35831956    EA   0.391     35831583    EB   0.391     35829410

EC   0.391     35822917    ED   0.391     35823825    EE   0.391     35827531    EF   0.391     35835787

F0   0.391     35846811    F1   0.391     35825090    F2   0.391     35832101    F3   0.391     35832957

F4   0.391     35839045    F5   0.391     35850406    F6   0.391     35836066    F7   0.391     35837913

F8   0.391     35831573    F9   0.391     35825461    FA   0.391     35827415    FB   0.391     35841653

FC   0.391     35830668    FD   0.391     35838418    FE   0.391     35834696    FF   0.391     35835358

 

Total bytes analyzed above: 9173114880; on device: 9173114880

Note: The longest consecutive sequence is 5 bytes long, and standard deviation is  0.000.

 

 

Program Ended.

 

Below is from another analysis and another secure erase pass. Note how well the random number generator distributes 1s and zeros.  Each of the 256 possible byte values are written 0.391% of the time, and standard deviation is rounded down to zero.  Subsequent passes almost always report the same standard deviation of 0.391% for every byte.

 

Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount   Byte Percent  TotalCount

 0   0.391     35833707     1   0.391     35833028     2   0.391     35833746     3   0.391     35825379

 4   0.391     35831376     5   0.391     35838552     6   0.391     35835833     7   0.391     35827386

 8   0.391     35836805     9   0.391     35823769     A   0.391     35833986     B   0.391     35824618

 C   0.391     35831460     D   0.391     35832262     E   0.391     35828086     F   0.391     35834474

10   0.391     35835466    11   0.391     35838283    12   0.391     35832077    13   0.391     35832956

14   0.391     35833265    15   0.391     35829840    16   0.391     35842722    17   0.391     35829533

18   0.391     35826237    19   0.391     35822378    1A   0.391     35833117    1B   0.391     35831175

1C   0.391     35838283    1D   0.391     35828460    1E   0.391     35839982    1F   0.391     35832747

20   0.391     35827162    21   0.391     35828758    22   0.391     35830946    23   0.391     35836360

24   0.391     35836717    25   0.391     35839408    26   0.391     35821040    27   0.391     35825631

28   0.391     35832739    29   0.391     35832075    2A   0.391     35834083    2B   0.391     35835180

2C   0.391     35839779    2D   0.391     35834717    2E   0.391     35837155    2F   0.391     35828021

30   0.391     35837106    31   0.391     35828067    32   0.391     35825498    33   0.391     35824125

34   0.391     35826869    35   0.391     35831339    36   0.391     35828222    37   0.390     35820030

38   0.391     35830800    39   0.391     35829814    3A   0.391     35832758    3B   0.391     35837251

3C   0.391     35823200    3D   0.391     35829394    3E   0.391     35830338    3F   0.391     35833421

40   0.391     35833429    41   0.391     35834238    42   0.391     35836923    43   0.391     35838558

44   0.391     35839667    45   0.391     35834352    46   0.391     35831685    47   0.391     35836688

48   0.391     35835000    49   0.391     35835931    4A   0.391     35836251    4B   0.391     35839509

4C   0.391     35837401    4D   0.391     35844091    4E   0.391     35829000    4F   0.391     35833787

50   0.391     35826644    51   0.391     35839255    52   0.391     35834924    53   0.391     35823499

54   0.391     35831763    55   0.391     35823681    56   0.391     35838006    57   0.391     35832848

58   0.391     35835740    59   0.391     35824553    5A   0.391     35832107    5B   0.391     35828643

5C   0.391     35831402    5D   0.391     35839455    5E   0.391     35836769    5F   0.391     35833087

60   0.391     35833868    61   0.391     35828431    62   0.391     35829213    63   0.391     35841511

64   0.391     35824372    65   0.391     35828010    66   0.391     35831059    67   0.391     35833943

68   0.391     35839063    69   0.391     35833839    6A   0.391     35821287    6B   0.391     35842340

6C   0.391     35828064    6D   0.391     35831843    6E   0.391     35821119    6F   0.391     35839082

70   0.391     35835218    71   0.391     35828147    72   0.391     35834652    73   0.391     35839950

74   0.391     35834714    75   0.391     35830325    76   0.391     35824354    77   0.390     35819387

78   0.391     35840984    79   0.391     35833362    7A   0.391     35828972    7B   0.390     35820215

7C   0.391     35832008    7D   0.391     35837922    7E   0.391     35840449    7F   0.391     35836522

80   0.391     35838705    81   0.391     35827309    82   0.391     35837329    83   0.391     35832091

84   0.391     35823291    85   0.391     35828190    86   0.391     35831407    87   0.391     35824976

88   0.391     35824871    89   0.391     35824309    8A   0.391     35840238    8B   0.391     35831508

8C   0.391     35828130    8D   0.391     35839372    8E   0.391     35840670    8F   0.391     35822145

90   0.391     35834018    91   0.391     35824506    92   0.391     35834537    93   0.391     35826688

94   0.391     35831448    95   0.391     35840754    96   0.391     35837172    97   0.391     35837407

98   0.391     35842095    99   0.391     35834791    9A   0.391     35830020    9B   0.391     35839427

9C   0.390     35819530    9D   0.391     35830908    9E   0.391     35832220    9F   0.391     35824178

A0   0.391     35833780    A1   0.391     35832884    A2   0.391     35830435    A3   0.391     35837062

A4   0.391     35833475    A5   0.391     35842450    A6   0.391     35843017    A7   0.391     35840131

A8   0.391     35824430    A9   0.391     35827486    AA   0.391     35829485    AB   0.391     35839303

AC   0.391     35835607    AD   0.391     35834223    AE   0.391     35823586    AF   0.390     35811523

B0   0.391     35831265    B1   0.391     35835937    B2   0.391     35826103    B3   0.391     35831500

B4   0.391     35826127    B5   0.391     35826918    B6   0.391     35832064    B7   0.391     35832895

B8   0.391     35827545    B9   0.391     35825590    BA   0.391     35838479    BB   0.391     35829588

BC   0.391     35832674    BD   0.391     35829762    BE   0.391     35842889    BF   0.391     35831542

C0   0.391     35834933    C1   0.391     35842573    C2   0.391     35828205    C3   0.391     35831076

C4   0.391     35831198    C5   0.391     35831663    C6   0.391     35822112    C7   0.391     35836354

C8   0.391     35838467    C9   0.391     35826302    CA   0.391     35835666    CB   0.391     35839544

CC   0.391     35833268    CD   0.391     35834774    CE   0.391     35827933    CF   0.391     35831123

D0   0.391     35833236    D1   0.391     35835632    D2   0.391     35829711    D3   0.391     35833305

D4   0.391     35833423    D5   0.391     35833328    D6   0.391     35838977    D7   0.391     35838977

D8   0.391     35843830    D9   0.391     35823848    DA   0.391     35839168    DB   0.391     35832321

DC   0.391     35830628    DD   0.391     35838210    DE   0.391     35823853    DF   0.391     35835573

E0   0.391     35830561    E1   0.391     35831060    E2   0.391     35829247    E3   0.391     35824495

E4   0.391     35836808    E5   0.391     35837159    E6   0.391     35838624    E7   0.391     35834402

E8   0.391     35833637    E9   0.391     35830347    EA   0.391     35833533    EB   0.391     35832394

EC   0.391     35825744    ED   0.391     35835509    EE   0.391     35828629    EF   0.391     35821286

F0   0.391     35845849    F1   0.391     35837271    F2   0.391     35831886    F3   0.391     35839247

F4   0.391     35834102    F5   0.391     35841838    F6   0.391     35833509    F7   0.391     35833341

F8   0.391     35835834    F9   0.391     35827056    FA   0.391     35850286    FB   0.391     35826441

FC   0.391     35837663    FD   0.391     35834206    FE   0.391     35834107    FF   0.391     35833501

 

Total bytes analyzed above: 9173114880; on device: 9173114880

Note: The longest consecutive sequence is 6 bytes long, and standard deviation is  0.000.

 

 

Program Ended.