.dmg提取问题

Question

我的外部硬盘上有磁盘映像文件。我尝试使用mac.dmg从7z x mac.dmg文件中提取文件，这就是我得到的：

Processing archive: mac.dmg

Extracting  0.MBR
Extracting  1.Type EE

Everything is Ok

Files: 2
Size:       250059350016

Compressed: 201276607141

我做了file 1.Type EE，得到了：

1.Type EE: GPT data structure (nonstandard: at LBA 0), version 1.0, GUID: 66741e19-807b-4f4f-a1e4-652d7892adf3, disk size: 488397168 sectors (sector size unknown)

我不知道该怎么做。

增编：

在与@the_Seppi讨论了这个问题之后，我在以下位置：

使用：gdisk -l ubun.img我得到：

Caution: invalid main GPT header, but valid backup; regenerating main header
from backup!

Caution! After loading partitions, the CRC doesn't check out!
Warning! Main partition table CRC mismatch! Loaded backup partition table
instead of main partition table!

Warning! One or more CRCs don't match. You should repair the disk!

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

****************************************************************************
Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.
****************************************************************************
Disk ubun.img: 488397168 sectors, 232.9 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 66741E19-807B-4F4F-A1E4-652D7892ADF3
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 488397134
Partitions will be aligned on 8-sector boundaries
Total free space is 13 sectors (6.5 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF00  EFI System Partition
   2          409640       487127591   232.1 GiB   AF00  Untitled 1
   3       487127592       488397127   619.9 MiB   AB00  Recovery HD

这样做：sudo apt-get install hfsprogs mkdir \mnt\backup sudo mount -o force,loop,offset=$((409640*512)) -t hfsplus ubun.img /mnt/backup/

我明白了：

mount: wrong fs type, bad option, bad superblock on /dev/loop0,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

然后试着dmesg | tail，我明白了：

[529744.283668] FAT-fs (loop0): Can't find a valid FAT filesystem
[529744.283832] hfsplus: unable to find HFS+ superblock
[530011.118941] EXT4-fs (loop0): VFS: Can't find ext4 filesystem
[530011.119017] EXT4-fs (loop0): VFS: Can't find ext4 filesystem
[530011.119052] EXT4-fs (loop0): VFS: Can't find ext4 filesystem
[530011.119127] FAT-fs (loop0): bogus number of reserved sectors
[530011.119130] FAT-fs (loop0): Can't find a valid FAT filesystem
[530011.119274] hfsplus: unable to find HFS+ superblock
[530073.047405] hfsplus: unable to find HFS+ superblock
[530292.332266] hfsplus: unable to find HFS+ superblock

Answer 1

从您可以看到的，该文件实际上是一个磁盘映像。您需要使用dmg2img (sudo apt-get install dmg2img)将其转换为img文件，然后可以在循环设备中挂载生成的img文件以浏览其内容：

mount -o loop example.img /home/you/dir