Hi,
p.lane wrote:
> ]# dd if=/dev/sdb1 of=/mnt/ntfs/ext_data/ext3.img bs=512 count=<size_of_data>
> / 512
Note that will do one read(2) and write(2) system call for every 512
bytes, potentially a lot of system calls with much overhead. It's
easier to do
dd if=/dev/sdb1 of=ext3.img bs=100k
to lessen the number of systems calls. A count isn't required in either
case since dd(1) will keep reading until end of file on sdb1 and write
all that's read, including the possibly partial 100KiB "block" at the
end.
Increasing the block-size further makes the copy slower again
eventually; if using gparted you can see it callibrate what a good
block-size is at the start of the copy operation.
Cheers, Ralph.
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