Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Can I dd if=/dev/sda of=/dev/sdd3 (copy drive to partition) ? Will it be a problem?

The source and destination drives with their respective partitions are as follows:

--Source Drive details--

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000551f2

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       29300   235346944   83  Linux
/dev/sda2           29300       30402     8849409    5  Extended
/dev/sda5           29300       30402     8849408   82  Linux swap / Solaris

--Destination Drive details--

Disk /dev/sdd: 1000.2 GB, 1000204883968 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x5c78d991

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1       64235   515960032+   7  HPFS/NTFS
/dev/sdd2           64235       89731   204798976    7  HPFS/NTFS
/dev/sdd3           89731      121602   256000000    7  HPFS/NTFS
share|improve this question
Yes, you can, but you should be careful when estimating sizes of source drive and target partition. The target should be more than source, in simple words. And structure of the drive will be lost until you copy it again back to the drive. – Danatela Oct 16 '13 at 2:50
@Danatela: Yes as I mentioned in a comment below, I checked the sizes: Source Drive (to be backup-ed) is 250 GB with file system 241 GB; Destination Partition (from an 1 TB external hard drive) is 244 GB. The size of source drive is bigger than destination partition but source file system is less than the partition. Will it be still a problem? – somnathchakrabarti Oct 16 '13 at 17:31
possible duplicate of Comparison of backup tools – psusi Oct 16 '13 at 19:10

Yes, it will be a problem. Drives contain a partition table, partitions do not. What is it that you are really trying to do?

share|improve this answer
I am trying to take a backup of my hard drive to a partition of an external hard drive. My hard drive is 250 GB with file system 241 GB whereas the partition of my external drive is 244 GB – somnathchakrabarti Oct 16 '13 at 17:26
@somnathchakrabarti, then you should use a proper backup tool, not dd. See – psusi Oct 16 '13 at 19:10
When I ran the dd command, it ran for 4 to 5 hours and then ended with an I/O error as given in… – somnathchakrabarti Oct 20 '13 at 19:20
I couldn't backup my data on my hard drive and had to re-install Ubuntu from a live USB installer (that I created earlier). But even after re-install, during bootloading, there is a screen as in… – somnathchakrabarti Oct 20 '13 at 19:21
It seems there is device mapping error because when my newly installed Ubuntu 12.04LTS is started, there are some device errors that I am receiving apart from networking issues. The installed ubuntu couldn't identify any networking connections or devices. Is there any way I can resolve the badblocks in device mapping sector? – somnathchakrabarti Oct 20 '13 at 19:22

Yes it will be a problem , Because Each and Every partition Using Different UUID, So Try to Get the UUID Information of Both Drive Which u going to restore and backup , Here u have mentioned the destination Drives are in NTFS Format so sure u going to face issue

share|improve this answer
But that's one of the 2 formats that are allowed when disk formatting. You can either choose Win_exFAT or NTFS. – somnathchakrabarti Oct 16 '13 at 17:33

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.