I have two hard disks with the same sizes - represented as /dev/sda and /dev/sdb. I am trying to copy /dev/sda on /dev/sdb. /dev/sda has one ext3 partition. /dev/sda and /dev/sdb have the same partition layout. What I do is use the following command:
dd if=/dev/sda of=/dev/sdb
When I mount the file system on /dev/sdb I see that not all of the changes are reflected on the device. In other words the disks are not the same. So it fails. And I don't seem to figure out why. Can this corrupt the partition table on /dev/sdb. Is this the proper way to clone a disk?
Well, I don't unmount the file system on /dev/sda before I start cloning it. But I am absolutely sure that nobody is writing on it while the cloning is executing.