disk cloning ?

hadimotamedi · 11-11-2013, 03:45 AM

Dear All
I needed to clone my disk to another hard drive . I did it as the following :
#dd if=/dev/sdb of=/dev/sdc
But after a while, the procedure ended with the "writing to /dev/sdc
input/output error" message.
Can you please let me know how can I overcome this as the fdisk now returns as "
#fdisk /dev/sdc
"I do not know how to handle files with mode 81a4
must set cylinders"
What can I do at know ?
Thank you

jpollard · 11-11-2013, 04:12 AM

It assumes that the two disks are the same size. sdc has to be at least as large as sdb or the copy will fail. And both disks need to be in LBA mode, as then there is no cylinder operations done.

hadimotamedi · 11-11-2013, 04:20 AM

Thank you for your help. Please be informed that both disks are 40GB. So what can I do next?

hadimotamedi · 11-11-2013, 04:43 AM

Please be informed that the second disk had the same geometry but got problem. So I tried to clone the first disk on it. Please comment.

onebuck · 11-11-2013, 06:28 AM

Hi,

Good LQ resource for the 'dd' command: Learn the DD command

You could try: Clonezilla Live 2.2.0-16 LiveCD to clone the drive.

Hope this helps.

hadimotamedi · 11-11-2013, 06:49 AM

Thank you for your reply. If I want to format the target hard disk can you please let me know how to do that ?

onebuck · 11-11-2013, 11:25 AM

Hi,

Quote:

Originally Posted by hadimotamedi

Thank you for your reply. If I want to format the target hard disk can you please let me know how to do that ?

'man mke2fs';

Quote:

NAME
mke2fs - create an ext2/ext3/ext4 filesystem

SYNOPSIS
mke2fs [ -c | -l filename ] [ -b block-size ] [ -D ] [ -f fragment-size ] [ -g blocks-per-group ] [ -G number-of-groups ] [ -i bytes-per-inode ] [ -I
inode-size ] [ -j ] [ -J journal-options ] [ -N number-of-inodes ] [ -n ] [ -m reserved-blocks-percentage ] [ -o creator-os ] [ -O feature[,...] ] [
-q ] [ -r fs-revision-level ] [ -E extended-options ] [ -v ] [ -F ] [ -L volume-label ] [ -M last-mounted-directory ] [ -S ] [ -t fs-type ] [ -T
usage-type ] [ -U UUID ] [ -V ] device [ blocks-count ]

mke2fs -O journal_dev [ -b block-size ] [ -L volume-label ] [ -n ] [ -q ] [ -v ] external-journal [ blocks-count ]

DESCRIPTION
mke2fs is used to create an ext2, ext3, or ext4 filesystem, usually in a disk partition. device is the special file corresponding to the device (e.g
/dev/hdXX). blocks-count is the number of blocks on the device. If omitted, mke2fs automagically figures the file system size. If called as
mkfs.ext3 a journal is created as if the -j option was specified.

The defaults of the parameters for the newly created filesystem, if not overridden by the options listed below, are controlled by the
/etc/mke2fs.conf configuration file. See the mke2fs.conf(5) manual page for more details.

See the 'man mke2fs' pages for option descriptions.

qrange · 11-11-2013, 12:25 PM

perhaps /dev/sdc has bad blocks, you should check S.M.A.R.T.

there is no need to format when using dd.

jefro · 11-11-2013, 03:33 PM

Checking the disk with some diags isn't a bad idea to start.

dd is a bit by bit. So, we might assume any number of issues. One common one is as suggested. The size is different. As to if drive is OK again suggested to test disk. Consider OEM diag cd too. They have best diag apps. Use memtest also. Use best quality cables and set bios to default or failsafe speeds. Could be selecting wrong ata setting. Some clone tools test it and adjust.

Fdisk might be used also to decide true size.

Some older systems may not like the drive if it has a large number of cylinders. Might have the chs limit jumper on it too.

Could always try clonezilla or redobackup.

hadimotamedi · 11-11-2013, 11:42 PM

>>perhaps /dev/sdc has bad blocks, you should check S.M.A.R.T.

Can you please explain how to check it with smart ?

chrism01 · 11-12-2013, 01:41 AM

http://www.techrepublic.com/blog/lin...r-hard-drives/ and refer http://smartmontools.sourceforge.net...martctl.8.html

Habitual · 11-12-2013, 10:43 AM

https://wiki.archlinux.org/index.php...tire_hard_disk says "This will clone the entire drive, including MBR (and therefore bootloader), all partitions, UUIDs, and data."

Code:

dd if=/dev/sdb of=/dev/sdc bs=4096 conv=notrunc,noerror

I did this 2 days ago, and while I don't have the disk yet, I called it successful when there were no "errors" reported,
and fdisk and cfdisk both reported the same same for both of them.

qrange · 11-12-2013, 10:59 AM

there's also a special version, 'ddrescue' for badblocks.

irgunII · 02-17-2014, 08:25 PM

Quote:

Originally Posted by Habitual

https://wiki.archlinux.org/index.php...tire_hard_disk says "This will clone the entire drive, including MBR (and therefore bootloader), all partitions, UUIDs, and data."

Code:

dd if=/dev/sdb of=/dev/sdc bs=4096 conv=notrunc,noerror

I did this 2 days ago, and while I don't have the disk yet, I called it successful when there were no "errors" reported,
and fdisk and cfdisk both reported the same same for both of them.

Is the if the 'source' and the of the drive you want to be cloned?

I have my system running on my sdb drive (don't ask) and would prefer to have it on my sda as it's newer, faster and quieter. Would I use

Code:

dd if=/dev/sdb of=/dev/sda bs=4096 conv=notrunc,noerror

?

Do I need to do this while still in runlevel 3 or can it be done while in kde and browsing the web (for example)?

jpollard · 02-18-2014, 06:48 AM

It is best to do it when /dev/sdb has no mounted partitions. Copying with it mounted allows for the possibility of an incomplete file being copied, which can cause some filesystem corruption - especially if files are being deleted.

Other than that restriction, you can do it anytime.