OT: fdisk

[Polytropon]

On Mon, 4 Oct 2010 07:08:58 -0700, Robert <traveling08 at cox.net> wrote:
> I have now a free 1TB drive for use. It is formatted as UFS. Should I
> remove formatting before I dd the 500GB drive to it? 

Not needed, as you're going to use it under the control of FreeBSD.
After formatting and mounting it, let's say as /mnt, use dd (or
ddrescue) to first get an 1:1 copy of the source disk.



> I tried the above process and here is what I have.
> 
> [root at asus64] ~# mdconfig -a -t vnode -u 10 -f /250extra/disk.img 
> [root at asus64] ~# mount -o ro /dev/md10 /mnt
> mount: /dev/md10 : Invalid argument

Of course. :-)



> [root at asus64] ~# mount_ntfs -o ro /dev/md10 /mnt
> mount_ntfs: /dev/md10: Input/output error

This indicates that the NTFS seems to be damaged and prevents
mount_ntfs from mounting it. Start with "baby steps": Is there
a valid partition table?

	# fdisk /dev/md10

You should now get a partition table.

Did you create disk.img by dd'ing da0 or da0s1? This may matter.



> [root at asus64] ~# ls -l /dev/md*
> crw-r-----  1 root  operator    0, 129 Oct  4 06:43 /dev/md10
> crw-r-----  1 root  operator    0, 130 Oct  4 06:43 /dev/md10s1
> crw-------  1 root  wheel       0,  66 Oct  1 14:43 /dev/mdctl
> [root at asus64] ~# mount -o ro /dev/md10s1 /mnt

Good. At least a bit.



> [root at asus64] ~# ls -l /mnt
> total 0
> [root at asus64] ~# df -h
> Filesystem           Size    Used   Avail Capacity  Mounted on
> <snip>
> /dev/ad12s1d         226G     59G    149G    28%    /250extra
> /dev/md10s1          451G     32G    383G     8%    /mnt
>                      ^^^^     ^^^
> [root at asus64] ~# ls -la /mnt
> total 0

Hmmm... you dd'ed the WHOLE disk to disk.img? Does the size look
reasonable?



> > Warren wrote:
> > It will give an exact copy of the first 250G, which also means it
> > will not resize the 500G filesystem into a working 250G version.
> 
> Same questions as above. Can I dd to a 1TB? And what format on the
> drive?

Format the target disk as UFS, as you do with any disk you want to
use for FreeBSD. Then dd (or ddrescue) the source disk to a file on
that target disk. Then "connect" this file to a memory disk (md)
device. Check the fdisk output for that device. Mount it. Get your
data off.



> I apologize again if I am coming off as dense. I have not used "dd"
> before as I have always used dump for backups. 

Correct: dump + restore are used for UFS backups, but in this case,
you need to deal with "Windows" stuff that does not support such
standard means. That's why you need dd to make an 1:1 copy to work
with it as you would work on the original disk.




-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...