Carlos & jdd, et al -- ...and then Carlos E. R. said... % % On 2015-05-26 15:42, jdd wrote: % > Le 26/05/2015 15:28, Carlos E. R. a écrit : % > % > I mean some block size option, some time ago (don't know for now), the % > default was 512 bytes and copying 1Tb would need several weeks :-). % % Ah, of course. Use a block of anything from 1 to 100 MB. "bs=100M % oflag=nocache" or something of the sort. Agreed. I routinely make complete copies of my 250G 7200rpm SATA drives via a dumb USB2 controller, and with dd if=/dev/sdX bs=64M of=local.big.sdX.file it takes me maybe three hours to write it to a RAIDed scratch vol. I haven't tried significantly different block sizes, and this is on a RAM-skinny machine (more than enough for Linux, of course) so I couldn't go to something like 512M anyway. Then I swap in the restore test drive and reverse the process and write it out in about five hours, after which I go and boot from it to make sure that it actually works :-) Actually, before I do any of this I mount the filesystem and then write 0s to the blank space for F in ceiling ( $FREESPACE / 32G ) do gzip -dc prepared.dev-zero.32G-bigfile.gz >/vol/tmp/BIGFILE.$F done rm /vol/tmp/BIGFILE.? so that my gzip later has lots of repeat chars instead of leftover binary garbage. That makes a lovely difference in the gzip even when I have less than 10% free space (I rarely get to start a second 32G chunk, sad as that is). Speaking of backups, I keep meaning to start a thread on that and not getting a chance to... Perhaps later this week :-) % % -- % Cheers / Saludos, % % Carlos E. R. HAND :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org