Yes, you can abort dd
.
Just go to the terminal where dd
is running and press Ctrl+C.
Aborting dd
will not roll things back to the way they were before dd
started writing a stream of data to the disk. But that's fine, because you don't need that.
If your goal is just to clear out all the partitions on the disk and make a new partition table, you can do this in any partitioning utility. It's fast, because it doesn't write over most of the disk. Data might still be recoverable, but old files won't pop up out of nowhere or anything of the sort.
(And if you do need to securely erase the disk, dd
might not be adequate for that.)
Writing a new partition table to the disk is traditionally what people mean when they say "low level format." Actually there's something else called that too, which is typically not possible through software, and which also doesn't involve writing data all over the disk. (Modern hard disks contain some data structures used internally by the drive firmware.) dd
will not write in those "low level" areas.
As for the problem that motivated you to run dd
on the drive in the first place, if creating a new partition table in GParted or other utilities doesn't fix it and make the disk's size appear correctly, I suspect dd
wouldn't improve on that situation either.
There might be something (physically) wrong with the drive, but I wonder if maybe you've come up against some strange bug in GParted (or the version of GParted you're using) instead. Do things work any differently with fdisk
? (fdisk
is not nearly as powerful as parted
or gparted
, but you don't need to move or resize any partitions, so it should be adequate to the task.)
If you haven't done so, I also recommend checking the drive for failure indicators and defects. Assuming it supports SMART (most drives these days do), you can use smartctl
(see also this guide). You can scan the drive for surface defects with badblocks
, though given how long dd
was taking to run, that might take a long time.
dd
is because you didn't specify a block size. Addbs=1M
(or 10M) should speed things up quite a bit and reduce the time taken to something more reasonable like a few hours.