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Questions tagged [dd]

This command is used to do low level copying of data.

Convert and copy a file, write disk headers, boot records, create a boot floppy. dd can make an exact clone of an (unmounted) disk, this will include all blank space so the output destination must be at least as large as the input.

For more info refer to the manpage.

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Simple scheme for backup virtual machine, which drawback of simple DD?

We've been struggling to create the consistent scheme for backup of KVM virtual machines under Proxmox control and Ceph as storage, but still quite often during the vzdump with a snapshot the virtual machine is going down 120: dic 05 04:51:47 INFO:…
Igor
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When copying VM filesystem over netcat, dd copies double the disk size

I'm attempting to copy the disk of a working headless virtualbox VM (VM1) on one server to a new VM (VM2) on a vCloud server. I don't have access to the host of VM2. The OS is Windows Server 2003 (32-bit) I start both VMs with a live Knoppix…
JivanAmara
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dd or cat - overload when read /dev/zero

I need reclamation thin disk, so Im trying fill zero on vhdd. But when I run it, so server is overload with 20k IOPS and full satured SAN network. Can you help me how I can slow b/w for this? E.g 10MB/s Tried this: ionice -c 3 dd if=/dev/zero…
Pavel
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handle multiple calls of rsync, dd and snapshot

The server runs the following operations often. It takes a snapshot of a logical volume, then backup up the content to the remote backup server. It is possible that multiple backups and transfer happen at the same time. Will too many rsync sessions…
Purres
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dd output file larger than input file when executed with conv=noerror,sync

I am trying to backup an LVM on one of my servers with the following command: dd bs=4M conv=noerror,sync if=/dev/vg_volgroup/LvmName | ssh myuer@myip "dd of=/home/myuser/LvmName bs=4M conv=noerror,sync" The disk from which I am reading this LVM…
user2284355
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dd unable to write to tape drive

I'm trying to dump our online backups to tape; for obvious reasons I want to encrypt the data on the tapes, so to write to the tape I need to tar everything up, pipe that to openssl to encrypt it, then write that to tape: tar c /etc | openssl…
fukawi2
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rsync, dd and then add to RAID 1, could cause database corrupted?

Firstly I have a HDD which has been setup as RAID, type Volume, not RAID 0 or RAID 1 ... and I wanna add one more HDD to setup a RAID 1 array. These bellow steps are what I've done. Detach from Server and dd whole disk from the old HDD to the new…
xuansamdinh
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Correct way to copy vm disk

I have a VM’s disk to copy from one host to another for live migration. I can think of two ways to copy the VM’s disk. Do a snapshot of the Logical Volume in the original host, create a Logical Volume in the destination host of the same size. Then…
Purres
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Benchmarking GlusterFS & NFS on AWS using iozone and dd gives different results

I have tried benchmarking GlusterFS vs NFS on Amazon Web Services (AWS) using a m1.medium sized EC2 instance. We use the AWS EBS as the block store, with a XFS file system. Running Ubuntu 12.04 using the standard packages. I used iozone and dd to…
psiphi75
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Cancel /dev/zero before it finishes?

To clear a large hard drive I was using dd if=/dev/zero of=/dev/sda. Only later I realized from reading more sources that the default block size is 512, and if I want the process to go quicker I should increase the block size to at least 4M. My…
user182417
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1. XFS: how to find path / directory of inodes 2. XFS in a file -o loop and ddrescue?

how to find the full original file/directory path of some damaged XFS inodes? and how to list the last modified few 10000 inodes (=edited or moved files/directories) rapidly among millions of total files? is it better to ddrescue only the…
jonas
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how to boot from a backup disk created by dd

I use dd command to backup a disk. # dd if=/dev/sda of=/dev/sdb but when I boot from the backup disk, I got a error message check filesystem failed! I do not know how to settle this problem. I thought the sdb is a copy of sda, so it can be…
user1070948
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Drive cloning dd or rsync/sync via KVM

I've got a crash and the system won't boot correctly. I am getting errors like: ata3.00: status: { DRDY } ata3.00: status: { UNC } What would be the best way to save the main drive to make the system boot again? I am looking at: Using DD for disk…
Thompson Smith
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Using dd command and running out of space while cloning drive to img

I have a problem with drive cloning. Im using dd on damaged disk with bad sectors trying to make an image from it. Im booting computer with Live Linux CD . Damaged disk: sda 146GB (NTFS) External drive: sdb 300GB (NTFS) After running the command…
Alan
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Clone Flash Drive in Linux using DD

dd if=/dev/sda of=/dev/sdb I want to create a clone a bootable USB stick. lets say sda is 2GB sdb is 32GB. The above line will create a replica but the usable size will be 2GB. How can I use the remaining 30GB? (resize partition or modify the…
Cocoa Dev
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