System lags when doing large R/W operations on external disks
I am having some issues with system-wide latency/lagging when doing large disk imaging operations on an Ubuntu 18.04 system. Here’s the system specs:
dd
Using dd to clone a disk while mounted – risks?
I want to clone a hard disk using dd. Because I want to keep a process on the machine alive continuously, I would like to do this while the filesystem is still mounted. I understand this is not the “ideal” way to do this, but it also seems from Googling that it is possible.
What does dd stand for?
I know very well what the command does, but man dd, info dd tell me: ‘Convert and copy a file’, as does GNU Coreutils.
What’s the POSIX way to read an exact number of bytes from a file?
Just hit this problem, and learned a lot from the chosen answer: Create random data with dd and get “partial read warning”. Is the data after the warning now really random?
Clone whole partition or hard drive to a sparse file
I like to clone a whole partition or a whole hard drive onto a larger external disk but like to create a sparse file. I often use dd for cloning, but it doesn’t support sparse files. As a workaround I used something like:
How to Create Bootable Windows 10 image in Debian?
Pseudocode but originally developed for Windows 7 iso file but applied for Windows 8 in the thread How to create bootable Windows 8 iso image in Linux? but it does not work with Windows 10 iso
Why is dd so slow with a bs of 100M
I just tried to overwrite a fast ssd using dd. Using the ubuntu boot image I typed in: dd if=/dev/zero of=/dev/sda bs=100M error writing '/dev/sda': No space left on device blah blah 256 GB copied, 1195.81 s 214 MB/s Isn’t that quite slow? And where is the bottleneck? What about the choice of block size? … Read more
Why dd takes too long?
I need to copy one disk to another. I tried with the command below and it takes nearly a day to copy 1 TB of disk in federo.