[NTLUG:Discuss] How to move data from one drive to another

[Robert Pearson]

On 8/4/05, John Thomas <jathomas at tacni.net> wrote:
> Thanks for all the advice, guys.  I see now that dd won't work since the
> disk geometries will be different.

I just got through working through all this while moving the contents
of an 80 GB drive to a 60 GB drive with a different geometry. Using
"dd" to copy the entire disk worked just fine.
Using "dd" to copy "a partition" between different disk geometries did
not work for me.
Actually the "dd" partition copy worked without error but I never
could get the new destination disk to boot right.

I used brian at pongonova.net's imaging recommendation of---

>> dd if=/dev/hda of=backup.image bs=1024

with the change to 

dd if=/dev/hda of=/dev/hdb bs=1024

since I was going disk-2-disk.
This transferred 3.5 GB at between 4-8 MB/s (Megabytes per second). 
I ran several different test scenarios and did not keep good
configuration notes.
The "bs=512" (the default) transferred at about 1 MB/s.

I then tried Chris Cox's recommendation of---
>> You can raise the block size if you want to use dd to
>> speed things up a bit (e.g. 8192k instead 1024 bytes)

dd if=/dev/hda of=/dev/hdb bs=8192k  (yes, that is "k" bytes)

This transferred at 18+ MB/s

I tried my Knoppix 3.9 LiveCD but the transfer was really slow. The
first one was 33 hours for 3.5 GB. Never did find the problem. It
should work.

I inserted the OS installation disk and booted up in the kernel image
for all further "dd" transfer.

> This would be simple, since I could continue to use the small drive to boot.

I believe this is a wonderful idea and maybe the "Best of all Possible Worlds".
All my "User Information" (/home, IoD, etc.) is on at least two
separate external disks. A primary and secondary synced with rsync.
The internal disk has only the OS and Apps. I have worked in shops
where "/opt" (or wherever the Apps go) was also on separate disk for
performance reasons. All the client/server environments I worked in
served the OS, Apps, Logins and User Information from separate
sources. It is still a good idea to have separate sources for these
even in Peer-to-Peer.

> I didn't think of the idea of simply moving, say /home, to the new
> drive.  Should I use fdisk to format the drive as Linux FS and then make
> a /home partition there?  Will the kernel find /home  on whatever drive
> it is on?  (Home is where most of the data is, partly because I'm
> running XP under VMWare).

VMware is the way to go. There are many experts for VMware on this
mailing list. I am not one of them. From the conversations I have seen
on the mailing list, I would have thought that installing a new disk
for Linux under VMware would be just like installing it under Linux
running stand-a-lone. It the new disk is to be shared with XP the file
system type must be shareable read/write.

Hope this helps,  Robert