# Manipulation of dd output file from partition



## jaymax (May 27, 2014)

FreeBSD 9.x. Disk fails to mount! I have copied the disk partition [MBR] from /dev/, the of - seems unreadable.  No errors reported.

`gpart show` of disk:

```
63  156344517     1  freebsd  [active]  (74G)
```

I have tried this on copied output (of) and on the input file (if) /dev/ada4 and /dev/ada4s1.
==>

```
dd if=ada4s1 conv=ascii of=asci_ada4s1 bs=1m
```
in an attempt to see if it can be converted to ASCII text format, - still unreadable.

Does anyone have any idea 

how to make it humanly readable?
how to extract or possibly save portions of it? or
should I discard the dd() approach and use dump() instead?


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## wblock@ (May 27, 2014)

So what format is the data?  Is it a UFS filesystem?  Is it several tied up in bsdlabel(8)s?  If you can identify that, it can be mounted with mdconfig(8).

Once again, dump(8) is the way to do this.  A mysterious 74G binary is not a good way to save data.


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## Crivens (May 28, 2014)

wblock@ said:
			
		

> Once again, dump(8) is the way to do this.  A mysterious 74G binary is not a good way to save data.


Please keep in mind that dump(8) only works on UFS file systems. Things like FAT or ZFS are not handeld.


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## wblock@ (May 28, 2014)

ZFS can send snapshots.  The point is that it's better to use a filesystem-aware tool to copy or back up data.  Once that high-level data is backed up, it can be restored (even to other filesystems) or accessed more easily.


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