On Freitag, 12. September 2014, 15:53:19 Joseph wrote: > I have two identical HD in a box and want to duplicate sda to sdb
OK, do you want to copy just the boot sector or clone the whole disk with all data on it? > I want sdb to be bootable just in case something happens to sda so I can > swap the drives and boot. > > Do I boot from USB and run: > dd if=/dev/sda of=/dev/sdb bs=512 count=1 > If you want to copy *all* data, why stop after one block? Omit the "count=1" and clone the whole disk. BTW: It might go a little faster of you increase the block size, lets say bs=4096. > fdisk -l /dev/sda > > Disk /dev/sda: 596.2 GiB, 640135028736 bytes, 1250263728 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: dos > Disk identifier: 0x000f2548 > > Device Boot Start End Blocks Id System > /dev/sda1 * 63 80324 40131 83 Linux > /dev/sda2 80325 16868249 8393962+ 82 Linux swap / Solaris > /dev/sda3 16868250 121740569 52436160 83 Linux > /dev/sda4 121740570 1250258624 564259027+ 83 Linux > > fdisk -l /dev/sdb > > Disk /dev/sdb: 596.2 GiB, 640133946880 bytes, 1250261615 sectors > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes
