Copy linux from disk to disk

Disk cloning

Disk cloning is the process of making an image of a partition or of an entire hard drive. This can be useful for copying the drive to other computers or for backup and recovery purposes.

Contents

Using dd

Using ddrescue

ddrescue is a tool designed for cloning and recovering data. It copies data from one file or block device (hard disc, cdrom, etc) to another, trying to rescue the good parts first in case of read errors, to maximize the recovered data.

To clone a faulty or dying drive, run ddrescue twice. For the first round, copy every block without read error and map the errors to rescue.map .

where X is the partition letter of the source and Y of the target block device.

For the second round, copy only the bad blocks and try 3 times to read from the source before giving up.

Now you can check the file system for corruption and mount the new drive.

File system cloning

This article or section needs expansion.

Using e2image

e2image is a tool included in e2fsprogs for debugging purposes. It can be used to copy ext2, ext3, and ext4 partitions efficiently by only copying the used blocks. Note that this only works for ext2, ext3, and ext4 filesystems, and the unused blocks are not copied so this may not be a useful tool if one is hoping to recover deleted files.

To clone a partition from physical disk /dev/sda , partition 1, to physical disk /dev/sdb , partition 1 with e2image, run

Disk cloning software

These applications allow easy backup of entire filesystems and recovery in case of failure, usually in the form of a Live CD or USB drive. They contain complete system images from one or more specific points in time and are frequently used to record known good configurations. See Wikipedia:Comparison of disk cloning software for their comparison.

See also Synchronization and backup programs for other applications that can take full system snapshots, among other functionality.

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Linux Copy One Hard Disk to Another Using dd Command

Q. How can I copy one hard disk to another using dd command?

A. dd command can copy disk in raw format. It will copy partition table and bootloader and all partitions within this disk. For example, you can copy /dev/sda to /dev/sdb (same size) using the following dd command. dd should complete with no errors, but output the number of records read and written.

Login as the root user (use sudo or su command)

Open terminal or shell prompt and type the following dd command:
# dd if=/dev/sda of=/dev/sdb
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• if=/dev/sda : Input disk (source)
• of=/dev/sdb : Output disk (destination)

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Comments on this entry are closed.

Hi,
Please check your steps. Instead of if & of you have written if twice

Is is possible to copy one disc to another, a bigger one?

I want to know the reply of Dorin’s question

It’s probably best to copy preserving permissions (cp -a) your install to a new filesystem and reinstall the bootloader on the new partition.

yes , its possible , do the dd if=/dev/sda of=/dev/sdb first and once done using GNU parted , resize option .

pls note : fdisk wont work if you try to expand after copy , parted will do the job.

please answer Dorin’s question…

I want to know the answer of Dorin’s question too. Thanks

I would also appreciate an answer please ….

I guess we will have to try to copy one small disk to a bigger one.

you can dd one smaller hdd to one larger hdd, depending on the tools, you can then resize the partition to fit the entire new hdd

You can copy a smaller disk to alarger one. But initially the Filesyem over the large disk will be exactly s it is over the smaller disk. Then if you’re using ext2 / ext3 you can directly modify the partition size using resize2fs command. If you’re using LVM then you’ll need to expand LVM first.

You can copy a small disk to a larger disk, and then resize the partition with gparted.
You can also copy one partition from one disk to another, and then resize that partition afterwards.
e.g. dd if=/dev/sdb1 of=/dev/sdc1

Again, you can use gparted to resize the partition afterwards.

I was looking if any one can provide me the instructions on how to resize my linux hard disk (sda)

I am unable to perform wirte command after I making the changes in fdisk /dev/sda command.
Please help me out with this.

You can try to boot your system with a ubuntu live cd, and start the partition editor (gparted) when the system is booted. Or use a linux recovery cd

You should not resize a partition you are working on (=mounted)

GNU ddrescue is better, since it shows progress, won’t make any errors, and you can interrupt it without worry.

I have a external hard drive of 250GB capacity mounted on /mnt/sda2.
The device is at /dev/sda2.
So, if i want to copy the complete hard drive to take a backup using this dd command.
Do i have to unmount it first and then use dd command.
There are actually two partitions in the hard drive i want to copy.
One is of 5.5GB other is of 63GB.
Can i copy both using dd command, if so, would i be able to preserve the filesytem for later recovery.

Hey, my question is something different.

I have a 55GB hard disk … but it has only 30 GB filled with partitions and remaining 25G I have not even extended,
now my question is if I have one more disk with 49GB hard disk … can I copy the 30GB data into the 49G disk … ?

pls reply me as soon as possible …. I need it very urgent .

I am learning the linux environment so that I need yours experince

I have one server with raid 5 and I want to image from all disk to the external disk??

How can I do this step??

If I clone a 1 Gig disk to a 3 Gig disk, can I add partitions to remaining 2 Gigs on new disk?

To all the people asking questions about whether or not a smaller disk will go onto a bigger disk – the answer is yes, and yes you can create additional partitions afterwards.

DD will just copy block by block what it finds – remember that if you are copying a bad drive you might need the extra parameter conv=noerror so it ignores the errors it finds.

DD can also be used to create a mirror file containing the hard drive as well – something like dd if=/dev/sda1 of=/mnt/sda2/sda1.img would create an image file of sda1 – and dd if=/mnt/sda2/sda1.img of=/dev/sda1 would write the image file back to the partition (bear in mind that obviously if your creating an image file you wouldn’t create it on the same partition because it’s going to be the same size as the partition!)

HELLO FRIENDS..
I JUST WANT TO KNOW THE COMMANDS… aix COPY COMMANDS FOR FROM HDD TO ANOTHER HDD
PLEASE
HLEP ME

In linux terminal, if you know your source and target drives, what others have mentioned should work.

” dd if=/dev/sda1 of=/dev/sdb1 ”
where ” if= ” is the input file and ” of= ” is the output file (aka the HDDs). In this example, dd would copy from partition one of disk one and write block by block to partition one of disk two. Make sure to check your disk/partition names on your system, this is just an example.

To make it faster, you may append ” bs=1M ” to increase the block read/write size. ” bs= ” referring to block size parameter. As another mentioned, adding ” conv=noerror ” will continue the operation even after an input/output error.

In this example, that would leave ” dd if=/dev/sda1 of=/dev/sdb1 conv=noerror bs=1M ”

Also look into the function “cp” which is different than “dd”

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Disk cloning in Linux using dd command

The dd command utility is a simple yet powerful and useful command available in Unix and Linux systems which is used to convert and copy files. Unix like systems treat all devices as files and these device files are located in the /dev directory in your system. So typically your hard disk drive is a file in the /dev directory with the prefix of hd or sd (depending on IDE or SCSI driver). This concept of device as files makes dd a perfect candidate for backup and restore of disk images or cloning some partitions or the entire disk.

This article shows you some examples of how to use the dd command to backup or clone drive partitions and entire drives.

You can use the fdisk command or check the /proc/partitions to view all the disk partitions in your system.

From the above output we can deduce that you have hard disks on your system and their device file names are sda and sdb. There are two partitions in sda which are sda1 and sda2 and we also know that sda1 is a boot partition.

How to clone a partition from one disk to another

The following are the steps to create a clone of a partition from one disk to another disk, lets say for example you want to clone sda1 partition to sdb1 . In this case sda is your source disk and sdb is the destination disk.

Step 1: Create a new partition in the destination disk if it does not already exist. You can use the fdisk command to create the new partition.

Step 2: Run the dd command.

• conv=sync,noerror tells dd command to continue copying after read errors and fill input block with nulls in case partial records.
• status=progress shows progress of the copy.
• bs=64M set the block size to copy at a time. Adjust this value could improve the copying speed

How to clone an entire disk

To clone an entire disk, say for example sda to sdb , run:

When you clone a entire disk, the destination disk will get all the partitions that are on the source disk.

How to create a disk image

Before you create a disk image backup, make sure no partitions on that disk are mounted and run the following command

where sdb is the disk file name and /path/to/backup.img is the path and filename of the backup image.

Compressed disk image

You could also compress the backup image with gzip as shown in the example below

Send disk image to remote system

You could send the backup image to a remote machine using ssh as in the below example.

Split the disk image by size

You can split the disk image in to smaller pieces of any size that you specify by passing the dd output through split command.

The above command splits the backup image file to smaller files of size 50MB or less. A two letter suffix will be added to the files. The resulting files will have names backup.img.gz.aa, backup.img.gz.ab, backup.img.gz.ac.

To join the split files into a single image file, you run the command

Restoring disk image

The below command restores the disk sdb from the image file backup.img .

To restore from a compressed backup image, use the gunzip command with dd

To restore from a backup image that is compressed and split, run:

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