26
votes
dd on entire disk, but do not want empty portion
Use dd, with the count option.
In your case you were using fdisk so I will take that approach. Your "sudo fdisk -l "produced:
Disk /dev/sda: 64.0 GB, 64023257088 bytes
255 heads, 63 sectors/...
19
votes
Linux / BSD "quickly" wipe a USB drive?
The Linux command to remove all disklabel and file systems signatures is:
wipefs -a /dev/sd###
Most modern flash disks and flash USB sticks are supporting TRIM / DISCARD / SCSI UNMAP. For USB you ...
18
votes
dd on entire disk, but do not want empty portion
While /dev/zeroing the free-disk-space and use dd conv=sparse/gz -c is possible, on huge disks with empty space running in 100s of GBs, /dev/zeroing is painfully slow - not to mention that as other ...
16
votes
Break up a dd image into multiple files
It is my command line:
dd if=/dev/sda bs=4M | gzip -c | split -b 2G - /mnt/backup_sda.img.gz
It will create 2GB files in this fashion:
backup_sda.img.gz.aa
backup_sda.img.gz.ab
backup_sda.img.gz.ac
...
15
votes
Accepted
Linux / BSD "quickly" wipe a USB drive?
The fastest way is to remove all partitions on the drive. This will "remove" also filesystems. And zero first megabyte (boot record and so).
dd if=/dev/zero of=/dev/da0 bs=1M count=1
and ...
10
votes
Linux / BSD "quickly" wipe a USB drive?
There's different kinds of USB storage devices.
If your device supports it,
blkdiscard /dev/da0
on Linux, or
trim /dev/da0
on FreeBSD
will tell the drive to just drop all data. That's going to be ...
8
votes
Best way to remove text from the beginning of a huge file
bunzip2 -c backup.sql.bz2 | \
sed -n '/-- Table structure for `mytable`/,$p'
Explanation:
-n suppress automatic printing of pattern space
Address range construction:
Start with regex
/-- Table ...
7
votes
Accepted
Does it involve network to copy a file within a NFS share?
NFSv4.2 does have a offload-copy operation which can do server-to-server copy without proxying data trough the client. Modern linux kernels (> 3.13?) supports that. I don't know about other servers....
7
votes
Accepted
dd: zero-out all the remaining unused space of a drive
The /zero-Tag is actually a file name. The command just copies zeros from the virtual File /dev/zero (infinite number of zeros) into /mnt/hdb/zero until the disk is full, or some other error occurs.
...
7
votes
Linux / BSD "quickly" wipe a USB drive?
I do not care about "securely" wiping the data I just want it wiped so I can re-establish the partition structure and filesystem from scratch
Just run mkfs on the partitions.
6
votes
Cloning a bitlocker encrypted disk
Since it seems like the original question was never answered, I've tested using GNU dd to clone a disk encrypted with Microsoft BitLocker (in my case it was a spinning disk to a SSD) and it worked ...
6
votes
Cloning data from a damaged SSD
Clonezilla might come handy in your situation. You can definitely copy mismatched partitions with it!
https://clonezilla.org/
5
votes
Create a VHD file from a Linux disk
You wrote that "QEMU is a Linux package", but is not fully true anymore.
One example of build of QEMU for Windows is as part of WinSetupFromUSB 1.8 program.
The other build of QEMU is in qemu-img for ...
5
votes
dd on entire disk, but do not want empty portion
The accepted answer is not right. I agree with the comment above. I use dd with count parameter to back up my disk on a regular base. Simply replace the BACKUP_FOLDER and letter of your device with "X"...
4
votes
Accepted
Repair FAT filesystem on image
You have made the image of your whole USB pen drive with your dd command. This means that the image includes also a partition table.
That is why you cannot mount the image directly as a file system.
...
4
votes
Accepted
Using DD to clone a 600GB drive using SSH to remote location with only 60 GB of allocated data [server migration]
Ok, guys... finally, server migration was executed with status SUCCESS! Data copy time was aprox 5hs 30Min. Command & total time:
dd if=/dev/sda bs=5M conv=fsync status=progress | gzip -c -9 | ssh ...
4
votes
Cloning data from a damaged SSD
Do you have to do it at partition level? It might be easier to move the files instead, as you wouldn't need to mess around with shrinking the old filesystem or anything like that. A cp -avx will do ...
3
votes
ddrescue -- which files are in error locations?
ddrutility was created for just this purpose.
I successfully got it to list affected NTFS files given a ddrescue mapfile in under 20 seconds.
It writes its log file in the current directory.
3
votes
Does it involve network to copy a file within a NFS share?
The "copy a file" operation is not a basic file-system operation such as read, write, open, close, and similar operations. See this page for a good explanation of the operations a filesystem has to ...
3
votes
Moving a Logical Volume directly from one server to another over the network?
First make sure that the logical volume is not mounted. If it is and you want to make a "hot copy", create a snapshot first and use this instead:
lvcreate --snapshot --name transfer_snap --size 1G
I ...
3
votes
Moving a Logical Volume directly from one server to another over the network?
First I would take a snapshot of the lv:
lvcreate --snapshot --name my_shot --size <thesize> /dev/<name of vg>/<name of lv>
After that you have to create a new lv on the new host (...
3
votes
Using DD for disk cloning
The most info was described in previous inserted recipies, but not all was described.
Under linux you can clone hard drive or partition by dd command.
Attention, when you'll make a mistake, you will ...
3
votes
Why does dd make the host unresponsive?
Short answer: the server become unresponsive because you filled almost all memory with dirty pages (ie: data to be flushed out).
Long answer: generally, writes do not push data to the backing device ...
3
votes
Cloning data from a damaged SSD
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.
Note: Disk ...
3
votes
Accepted
Cloning data from a damaged SSD
You have to shrink the PV before cloning it with dd, but read only status of the SSD prohibits this.
But, using an overlay difference image you can still do it. In general it is the same as I ...
2
votes
Cloning a bitlocker encrypted disk
You'll find that AOMEI and other backup solutions can clone Bitlocker drives, but the result is an unencrypted drive (using sector by sector copy, and the bitlocker source has to be unlocked). Casper ...
2
votes
PXE booting .IMG and .DD images
First of all, ensure memdisk is actually present on your TFTP server and can be served to clients. It's not a magic invocation, memdisk is a separate component of syslinux.
Secondly, loading ISOs in ...
2
votes
Backup and Restore Using dd and gzip
You can use ddrescue with its -S option:
-S
--sparse
Use sparse writes for outfile. (The blocks of zeros are not actually allocated on disc). May save a lot of disc space in some cases. Not all ...
2
votes
Accepted
dd's relation with page cache
dd does not directly use page cache, it does I/O which is automatically cached.
Dropping a cache simply because something was committed is inefficient. The next read would need to come from the ...
2
votes
Accepted
Find out exact location of GRUB / GRUB not working after copying disk image
In the GRUB2-created MBR, starting at offset 0x5c, there is a little-endian 64-bit value indicating the number of the next disk block to be loaded. This is often block 0x00000000 00000001, i.e. the ...
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