When I tried to follow the dd example on the bandwidth guideline page (http://xillybus.com/doc/bandwidth-guidelines), I got the following errors.
- Code: Select all
$ dd if=/dev/zero of=/dev/xillybus_sink bs=128k
dd: failed to open ‘/dev/xillybus_sink’: Permission denied
$ sudo dd if=/dev/zero of=/dev/xillybus_sink bs=128k
[sudo] password for <my account>:
dd: error writing ‘/dev/xillybus_sink’: No space left on device
63626+0 records in
63625+0 records out
8339537920 bytes (8.3 GB) copied, 1.44206 s, 5.8 GB/s
$ dd if=/dev/xillybus_source of=/dev/null bs=128k
dd: failed to open ‘/dev/xillybus_source’: No such file or directory
My questions are as follows:
(1) Are the outputs normal? Did I really successfully write things into xillybus_sink? It seems that I did successfully write to it with a 5.8GB/s bandwidth, but why is it complaining "dd: error writing /dev/xillybus_sink: No space left on device"?
(2) I've already added the udev rule for xillybus, which changes the permission of xillybus subsystem to 666, but why did I still need to use sudo access to write to xillybus_sink?
(3) The guideline page instructed to use /dev/xillybus_source to test the bandwidth of the other direction. But on my computer I couldn't find the device /dev/xillybus_source as instructed in the same guideline page. Is it normal?
Any hint or suggestion is much appreciated!