My OS is Ubuntu 10.10. I have burned Ubuntu 11.04 into a CD. Now I tried to check the CD following https://help.ubuntu.com/community/HowToMD5SUM#Check%20the%20CD, as following:
$ ls -l
-rwxrwx--- 1 root plugdev 718583808 2011-05-19 10:26 ubuntu-11.04-desktop-i386.iso
$ dd if=/dev/cdrom bs=1 count=718583808 | md5sum
dd: reading `/dev/cdrom': Input/output error
718581760+0 records in
718581760+0 records out
718581760 bytes (719 MB) copied5f0528a1b0a834bcf6d25f0b52d97736 -
, 3918.18 s, 183 kB/s
My questions are:
- I found my CD appears as /media/Ubuntu 11.04 i386, why not verify it, but to verify /dev/cdrom?
- why did I get "dd: reading `/dev/cdrom': Input/output error", and only 718581760 out of 718583808 bytes are processed?
- How shall I check the CD then?
Thanks and regards!