sfdisk mostra valor impossível e (c, h, s) esperado em outro sistema

Question

No meu sistema Raspbian (Jessie) sudo sfdisk -lV /dev/mmcblk0 (sfdisk do util-linux 2.25.2) me mostra

Disk /dev/mmcblk0: 3923936 cylinders, 4 heads, 16 sectors/track
Units: cylinders of 32768 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/mmcblk0p1        128    2143    2016      64512    e  W95 FAT16 (LBA)
                start: (c,h,s) expected (128,0,1) found (0,130,3)
                end: (c,h,s) expected (1023,3,16) found (8,138,2)
/dev/mmcblk0p2       2144  329823  327680   10485760   83  Linux
                start: (c,h,s) expected (1023,3,16) found (8,138,3)
                end: (c,h,s) expected (1023,3,16) found (1023,254,63)
/dev/mmcblk0p3     329824  591967  262144    8388608   83  Linux
                start: (c,h,s) expected (1023,3,16) found (1023,254,63)
                end: (c,h,s) expected (1023,3,16) found (1023,254,63)
/dev/mmcblk0p4     591968  3497439  2905472   92975104    7  HPFS/NTFS/exFAT
                start: (c,h,s) expected (1023,3,16) found (1023,254,63)
                end: (c,h,s) expected (1023,3,16) found (1023,254,63)
sfdisk: Warning: no primary partition is marked bootable (active)
This does not matter for LILO, but the DOS MBR will not boot this disk.
sfdisk: start of partition 1 has impossible value for head: 130 (should be in 0-3)

No entanto, no sistema VirtualBox do meu VirtualBox Debian (stretch / testing) rodando em um host Windows 10 com o cartão SDXC plugado via um velho leitor de cartão USB 2.0 sudo sfdisk -lV /dev/sdc (sfdisk do util-linux 2.29.1) mostra

Disk /dev/sdc: 119.8 GiB, 128579534848 bytes, 251131904 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x102c03ad

Device     Boot    Start       End   Sectors  Size Id Type
/dev/sdc1           8192    137215    129024   63M  e W95 FAT16 (LBA)
/dev/sdc2         137216  21108735  20971520   10G 83 Linux
/dev/sdc3       21108736  37885951  16777216    8G 83 Linux
/dev/sdc4       37885952 223836159 185950208 88.7G  7 HPFS/NTFS/exFAT
Remaining 27295744 unallocated 512-byte sectors.

Eu criei o cartão SD de uma imagem Raspbian recente com este adaptador USB e adicionei mais partições depois.

Por que o Raspbian reporta algo diferente? O que significa c,h,s e impossible value ? Não parece certo. Deve me preocupar?

    

Answer 1

Should it worry me?

Não. Geralmente é irrelevante para o Linux. A menos que você tenha notado que seu sistema não inicializa porque o gerenciador de inicialização confia em valores (c, h, s).

A versão mais recente de sfdisk remove qualquer código para manipulação (c, h, s). Na página man, eu entendo que os modos de compatibilidade com versões anteriores do DOS foram removidos.

Por exemplo link

If you still rely on old default cylinders than be careful with update. Frankly, LBA addressing is mandatory since ATA-3 (1997) and supported by Linux since beginning.

( Tipos de partição para o modo LBA estão disponíveis desde MS Windows 95 . A significância dos limites do cilindro parece ter sido descartada por < href="https://en.wikipedia.org/wiki/Cylinder-head-sector"> Windows Vista e mais recente).

    

Answer 2

Testes de acordo com comentários

Eu testei o adaptador USB com um cartão SD de backup no Raspberrry e vi o mesmo aviso:

raspberrypi:~$ sudo sfdisk -lV /dev/sdb

Disk /dev/sdb: 1015 cylinders, 32 heads, 62 sectors/track
sfdisk: Warning: The partition table looks like it was made
  for C/H/S=*/113/51 (instead of 1015/32/62).
For this listing I'll assume that geometry.
Units: cylinders of 2950656 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdb1   *      2+    349-    347-    999552    7  HPFS/NTFS/exFAT
                start: (c,h,s) expected (2,90,13) found (1,1,1)
                end: (c,h,s) expected (349,77,18) found (125,112,51)
/dev/sdb2          0       -       0          0    0  Empty
/dev/sdb3          0       -       0          0    0  Empty
/dev/sdb4          0       -       0          0    0  Empty
sfdisk: Warning: partition 1 does not start at a cylinder boundary
sfdisk: Warning: partition 1 does not end at a cylinder boundary
sfdisk: partition 1: start: (c,h,s) expected (8,4,9) found (1,1,1)
sfdisk: end of partition 1 has impossible value for head: 112 (should be in 0-31)

Outro dispositivo USB com uma única partição vfat mostrou

Disk /dev/sdb: 1015 cylinders, 32 heads, 62 sectors/track
sfdisk: Warning: The partition table looks like it was made
  for C/H/S=*/113/51 (instead of 1015/32/62).
For this listing I'll assume that geometry.
Units: cylinders of 2950656 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdb1   *      2+    349-    347-    999552    7  HPFS/NTFS/exFAT
                start: (c,h,s) expected (2,90,13) found (1,1,1)
                end: (c,h,s) expected (349,77,18) found (125,112,51)
/dev/sdb2          0       -       0          0    0  Empty
/dev/sdb3          0       -       0          0    0  Empty
/dev/sdb4          0       -       0          0    0  Empty
sfdisk: Warning: partition 1 does not start at a cylinder boundary
sfdisk: Warning: partition 1 does not end at a cylinder boundary
sfdisk: partition 1: start: (c,h,s) expected (8,4,9) found (1,1,1)
sfdisk: end of partition 1 has impossible value for head: 112 (should be in 0-31)

Eu também testei dois outros leitores de cartão USB simples (infelizmente todos sem suporte a SDHC e SDXC) e todos eles mostraram o mesmo resultado.

Eu estou querendo saber o que as outras pessoas vêem para

sudo sfdisk -lV /dev/mmcblk0