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Re: virtualisation

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On 5/23/23 20:35, mick.crane wrote:

> root@pumpkin:/home/mick# dd bs=512 count=33 if=/dev/sda skip=468862095 | 
> hexdump -C >dump.txt
> 33+0 records in
> 33+0 records out
> 16896 bytes (17 kB, 16 KiB) copied, 0.0114308 s, 1.5 MB/s
> root@pumpkin:/home/mick# nano dump.txt
> 00000000  d0 80 47 bf 2b 38 99 33  54 ee ec 10 02 26 2a 11 
> |..G.+8.3T....&*.|
> 00000010  8b f6 af 00 1e a7 6f 28  22 63 84 18 3b 60 5b fb 
> |......o("c..;`[.|
> ..........
> 000041e0  19 d0 6a 27 a9 7e e9 e0  21 24 82 de 64 66 58 41 
> |..j'.~..!$..dfXA|
> 000041f0  7d 12 94 8f f4 f3 a0 3a  f1 4a b9 53 fb ac 8d 6e 
> |}......:.J.S...n|
> 00004200


The sectors are outside the range of partition sda5.  In an ideal 
BIOS-MBR configuration, they should be zeroed.  The fact that they are 
not means something set them, but it has hard to tell from that limited 
output if those bytes correspond to a secondary GPT partition table, 
encrypted file system leftovers, or something else.


The first 16 bytes of the secondary GPT header in the last block are the 
best clue -- they contain an signature, a revision, and a header size:

https://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_table_header_(LBA_1)


My UEFI-GPT machine matches the WikiPedia specification exactly:

2023-05-24 01:09:37 root@taz ~
# dd bs=512 count=1 if=/dev/sda skip=117231407 status=none | hexdump -C 
| head -n 1
00000000  45 46 49 20 50 41 52 54  00 00 01 00 5c 00 00 00  |EFI 
PART....\...|


Try this command on your machine:

468862128 - 1 = 468862127

# dd bs=512 count=1 if=/dev/sda skip=468862127 status=none | hexdump -C 
| head -n 1


David

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Thread

virtualisation "mick.crane" <mick.crane@gmail.com> - 2023-05-22 20:50 +0200
  Re: virtualisation Dan Ritter <dsr@randomstring.org> - 2023-05-22 21:30 +0200
    Re: virtualisation Mark Allums <maa@allums.com> - 2023-05-22 21:40 +0200
      Re: virtualisation "Andrew M.A. Cater" <amacater@einval.com> - 2023-05-22 21:50 +0200
    Re: virtualisation Dan Ritter <dsr@randomstring.org> - 2023-05-22 22:40 +0200
  Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-23 00:20 +0200
    Re: virtualisation Charles Curley <charlescurley@charlescurley.com> - 2023-05-23 15:10 +0200
    Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-24 00:10 +0200
      Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-24 10:40 +0200
        Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-24 20:50 +0200
      Re: virtualisation Michael <ml@hemathor.de> - 2023-05-26 10:20 +0200
        GPT backup table, was Re: virtualisation "Thomas Schmitt" <scdbackup@gmx.net> - 2023-05-26 11:50 +0200
          Re: GPT backup table, was Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-26 12:50 +0200
          Re: GPT backup table, was Re: virtualisation Michael <ml@hemathor.de> - 2023-05-27 11:40 +0200
            Re: GPT backup table, was Re: virtualisation Dan Ritter <dsr@randomstring.org> - 2023-05-27 17:50 +0200
            Re: GPT backup table, was Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-28 05:20 +0200
          Re: GPT backup table, was Re: virtualisation zithro <slack@rabbit.lu> - 2023-05-27 19:20 +0200
            Re: GPT backup table, was Re: virtualisation Stefan Monnier <monnier@iro.umontreal.ca> - 2023-05-27 20:00 +0200
        Re: virtualisation David Christensen <dpchrist@holgerdanske.com> - 2023-05-26 12:40 +0200
    Re: virtualisation Max Nikulin <manikulin@gmail.com> - 2023-05-25 18:30 +0200

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