cdck (CD/DVD check tools) is a simple console program to verify CD/DVD quality. The known fact is that even if all files on the disc are readable, some sectors having bad timing can easily turn into unreadable ones in the future.
To get an idea about a disc cdck reads it sector by sector, keeping all reading timings and then tells you its verdict. Optionally it can write the timing table into text file usable by gnuplot program, so you can draw some graphs out of it.
Install cdck in ubuntu
sudo apt-get install cdck
cdck [-d /dev/devname] [-i] [-t] [-v] [-p] [-o plot-file.dat]
-d CD/DVD device name, default is /dev/cdrom
-i Print CD/DVD information and quit, perform no timings (default mode)
-t Perform timing test
-p Save data for gnuplot(1) program
-o specify plot file, ./cdck-plot.dat is the default
-V Print version
-v Verbose operations
To actually plot your data you have to start gnuplot and plot the datafile:
gnuplot> plot "cdck-plot.dat"