I tried to create device mapper with dmsetup as followed:dmsetup create error_disk0 20000 linear /dev/loop0 020000 1 error20001 20959 linear /dev/loop0 20001Then I check with command below:dd if=/dev/mapper/error_disk of=/dev/null bs=1k count=10000  => Result OKdd if=/dev/mapper/error_disk of=/dev/null bs=1k count=10001  => Result IO errorSo the result is right as I expected.But then I mount as follow:mke2fs /dev/mapper/error_disk mount /dev/mapper/error_disk  /mnt/I mounted successful. But when I copy the file with size is 20Mb to /mnt/ and copy successful. But I think the coping must to fail because this error disk is error at sector 20000 (10Mb). So how can I do to this coping is fail.
Mount success but property of device mapper that dmsetup create is lost
filesystems;device mapper