If I try to change the installation directory, I see the following error message:
Cannot obtain a lock on data directory /cdrom. Bitcoin Core is probably already running. No such file or directory.
For bitcoin core specifically, just copy all of the binaries to a folder in sdb1 and run the program from there.
If I try to copy the binaries to a folder in /cdrom I get the following message:
The folder “bin” cannot be copied because you do not have permissions to create it in the destination.
Then check your permissions. Make sure that you have permission to copy things to /cdrom. Make sure that you have permissions to even move the bin folder.