On 12/30/2010 12:11 PM, Per Jessen wrote:
Sampsa Riikonen wrote:
Dear List,
I have duplicated my hard disk using "dd", including the boot partition to another hard disk (a sata drive in a usb box). Now I am trying to boot from this duplicated disk, but nothing happens.. grub does not start at all.
Hi Sampsa
using dd for copying a harddisk assumes source and target are the same, which I am guessing yours are not. You might fare better by copying across the contents of the filesystem(s), e.g. using rsync, and (re-)preparing the target drive for booting.
Well that depends... Using dd will copy the filesystems/partitions from one device to another. dd should work without an issue as long as the target drive is greater or equal to the size of the source. If you want to grow the file system after the dd copy, the copy a partition, then use gparted (or the like) to grow the partition before copying the next one. I have successfully moved Linux installs, windows installs and virtualbox VDI's that way. After you move the partitions to a new disk, you still may need to boot with the install disk because the grub device designations will surely have changed. (/dev/disk/by-id, etc..) Here are my notes for 'dd copy MBR and/or Partition Table' MBR is divided into 3 sections: 1. Bootstrap . 446 bytes 2. Partition table. 64 bytes 3. Signature. 2 bytes Copy MBR & Partition Table: (only for same sized partitions) dd if=/dev/sda of=/dev/sdb bs=512 count=1 Copy MBR only: dd if=/dev/sda of=/dev/sdb bs=446 count=1 Make a backup first: Here’s what I do to copy just the MBR from a hdd: dd if=/dev/sda of=mbrbackup bs=512 count=1 Now to restore the image to any hdd: dd if=mbrbackup of=/dev/sdb bs=446 count=1 Backing up and restoring the MBR and boot sector(s): It is very easy to back up these essential parts of your disk. You will need to copy (part of) the MBR, and boot sectors in order to have your new system boot like the old one. To save the MBR to a file (this contains the partition table too): dd if=/dev/hda of=hda-mbr-full bs=512 count=1 To save the MBR, without the partition table, to a file: dd if=/dev/hda of=hda-mbr-nopart bs=446 count=1 To save a boot sector (e.g. partition 3) to a file: dd if=/dev/hda3 of=hda3-bootsect bs=512 count=1 Good luck :p -- David C. Rankin, J.D.,P.E. Rankin Law Firm, PLLC 510 Ochiltree Street Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org