Cannot change directory in Terminal if target has spaces in it
Spaces in file names can be a hassle in the shell. Your best solution would be to both wrap the name in " characters and use the shell's built in completion to get the right name. 

Type cd "/Volumes/TOSH then type a tab and the shell will complete the name with any spaces and non-standard characters included. If the tab completes the entire path then the shell will even insert a "/ at the end so you are ready to then hit return.

Note that standard bash completion will work on file paths and names for most shell commands, not just cd.