Web lists-archives.com

Re: BIOS Can Not Find Disk




On 12/04/17 07:21, David Wright wrote:
I recently reformatted a disk thus:

puck:                       GPT-style, master

Part #  filesys size        code    rôle
puck    -       1007KiB             partition tables and alignment space
puck01  -       3MiB        EF02    bios-boot for Grub (bios_grub flag)
puck02  FAT32   496MiB      EF00    EFI (boot flag)
puck03  ext2    500MiB      8300    /boot (unencrypted)
…

Your console session is incomplete -- you did not copy/paste your command.


which gdisk shows as

Number  Start (sector)    End (sector)  Size       Code  Name
    1            2048            8191   3.0 MiB     EF02  BIOS boot partition
    2            8192         1023999   496.0 MiB   EF00  EFI System
    3         1024000         2047999   500.0 MiB   8300  Linux filesystem
…

As above; but at least you dropped a clue, "gdisk".


Here is some more info:

# gpart -d -vvv /dev/sda

dev(/dev/sda) mss(512) chs(1946/255/63)(LBA) #s(31277232) size(15272mb)
Primary partition(1)
   type: 238(0xEE)(UNKNOWN)
   size: 15272mb #s(31277231) s(1-31277231)
   chs:  (0/0/1)-(1023/254/63)d (0/0/2)-(1946/233/63)r
   hex:  00 00 01 00 EE FE FF FF 01 00 00 00 AF 40 DD 01

Primary partition(2)
   type: 000(0x00)(unused)
   size: 0mb #s(0) s(0-0)
   chs:  (0/0/0)-(0/0/0)d (0/0/0)-(0/0/0)r
   hex:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Primary partition(3)
   type: 000(0x00)(unused)
   size: 0mb #s(0) s(0-0)
   chs:  (0/0/0)-(0/0/0)d (0/0/0)-(0/0/0)r
   hex:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Primary partition(4)
   type: 000(0x00)(unused)
   size: 0mb #s(0) s(0-0)
   chs:  (0/0/0)-(0/0/0)d (0/0/0)-(0/0/0)r
   hex:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00


dev(/dev/sda) master boot record (w/o partition table):
   0000:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0010:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0020:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0030:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0040:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0050:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0060:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0070:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0080:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0090:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   00A0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   00B0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   00C0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   00D0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   00E0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   00F0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0100:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0110:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0120:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0130:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0140:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0150:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0160:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0170:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0180:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   0190:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
   01A0:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .

# gdisk -l /dev/sda
GPT fdisk (gdisk) version 1.0.1

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 31277232 sectors, 14.9 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): C078C1DF-29A5-4552-917D-995FF9946D9F
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 31277198
Partitions will be aligned on 2048-sector boundaries
Total free space is 19560557 sectors (9.3 GiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         1953791   953.0 MiB   EF00  ESP
   2         1953792        11718655   4.7 GiB     8E00  stretch

# fdisk -l /dev/sda
Disk /dev/sda: 14.9 GiB, 16013942784 bytes, 31277232 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: gpt
Disk identifier: C078C1DF-29A5-4552-917D-995FF9946D9F

Device       Start      End Sectors  Size Type
/dev/sda1     2048  1953791 1951744  953M EFI System
/dev/sda2  1953792 11718655 9764864  4.7G Linux LVM


Is the absence of a partition like puck01 on your disk a significant
factor in your failure to install grub?
ie where's grub going to place itself?

I initially let d-i/partman automagically partition the SSD, looked at the table it generated, and saw a ESP partition, a swap partition, and a root partition. I then wipe the first and last megabyte, created the GPT partition with parted, and then proceeded with the complex disk layout I really wanted. Unfortunately, debian-9.1.0-amd64-xfce-CD-1 d-i blew up trying to install GRUB, so I don't know where GRUB ends up when UEFI firmware and GPT partitioning is done correctly. That's why I plan to try again with the simplest automagic partitioning and see what happens.


STFW I found another useful article:

http://www.rodsbooks.com/efi-bootloaders/grub2.html


David