Re: File transfer
On 02/27/2015 07:48 PM, Maureen L Thomas wrote:
If I understand you correctly then I only back up data, not the system.
You have an excellent point and although I have never, so far at least,
had a large problem losing my system or data I do see the advantage to
doing just what you have said. I will be buying the book you suggested
and hopefully get through enough to do a back up of the new system
before I actually go on line with it.
Thank you for the info.
You're welcome. :-)
I seem to recall that the book is good for concepts and advice, but
light on implementation details.
To take an image of your system drive:
1. Shut down the computer.
2. Connect your image destination drive (e.g. USB external hard drive).
3. Boot the computer using a Debian installation disc or USB drive. I
use the Wheezy "netinst" image. You may need to configure your BIOS,
press F10, change the ordering of devices connected to USB ports, etc..
4. Choose Advanced Options -> Rescue Mode. Proceed through
configuration screens which may vary from mine depending upon your
network environment (select language, select location, configure
keyboard, enter host name, enter domain name, configure clock). Don't
enter encryption passphrases, configure LVM, mount drives, etc.. When
you get to the "Enter rescue mode" screens, choose "Do not use a root
file system" -> "Execute a shell in the installer environment" ->
"Continue". This will give you an "ash" shell prompt in the "BusyBox"
environment, and raw access to all the connected drives.
5. Be very careful typing commands -- you are running as root, and one
fumbled key stroke could be disastrous. Double check every command line
before pressing the <Enter> key.
6. Figure out the path to your system drive, how many blocks are in use
on your system drive (use the "start" sector number for the free space
after the last partition), your image destination drive, and your image
destination partition. I use "parted":
# parted /dev/sda u s p free
...
For my computer "p43200", /dev/sdc is the system drive, 28125184 sectors
are in use, /dev/sda is the image destination drive, and /dev/sda1 is
the image destination partition.
7. Mount the image destination partition:
# mount /dev/sda1 /mnt
8. Copy the system drive raw device contents to a file on the image
destination file system:
# dd if=/dev/sdc
of=/mnt/image/p43200/p43200-20150227-2200-debian-7-amd64-xfce-op.img
count=28125184
9. Create a checksum file:
# cd /mnt/image/p43200
# md5sum -b p43200-20150227-2200-debian-7-amd64-xfce-op.img >
p43200-20150227-2200-debian-7-amd64-xfce-op.img.md5
Make the modification times match:
# touch -r p43200-20150227-2200-debian-7-amd64-xfce-op.img
p43200-20150227-2200-debian-7-amd64-xfce-op.img.md5
10. Exit the shell:
# exit
11. Choose "Reboot the system". Wait for the installer to shut down
and the computer to reach POST. Power off the machine. Disconnect your
Debian installation USB drive and your image destination drive.
Verifying the image by wiping the system drive and then restoring the image:
1. Wipe the system drive using your tool of choice (such as the drive
manufacturer's bootable utility disc).
2. Perform imaging steps 1 through 7, above.
3. Verify the checksum of the image file:
# cd /mnt/image/p43200
# md5sum -c p43200-20150227-2200-debian-7-amd64-xfce-op.img.md5
4. Restore the image file to the system drive:
# dd if=p43200-20150227-2200-debian-7-amd64-xfce-op.img of=/dev/sdc
Look at the block count when done -- it should match what you
started with. (Things might be goofy if the system drive and the image
destination drive use different block sizes.)
5. Perform imaging steps 10 and 11, above.
6. Boot the system, log in, and have a look around. If everything
looks good, proceed with using the computer. If it's broken, wipe the
system drive, do a fresh install, and try again.
David
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