I am using Ubuntu 10.10. I have 2 * 1TB external hard drives for my data backups. These clearly show as 1TB each one, and I have them named as BACKUP01 & BACKUP02. When I try to move a backup of 38GB to one or other of my hard drives I get the message 'Error while copying to "BACKUP01". There is not enough space on the destination. Try to remove files to make space. There is 21.9 GB available, but 38.1 GB is required.' The problem with this message is that there ought to be much more that 21.9 GB left. I have used only 62.3 GB. So bearing in mind that the disk is one terrabyte and that there is 62.3 GB used, I ought to have 947.7 GB free space, not 21.9GB. I am trying hard to work out what is going on here. The only thing I can think of is that past deletes although they may have freed up the logical space, have not freed up the physical space. I have not come across this type of thing before. Normally the elimination of logical files should have cause the equivalent free up of physical space.

I would be interested in getting behind the graphical interface and seeing what might be going on. I do not know enough about unix type commands to even know how to navigate to what is my external hard drive. I am thinking of opening a terminal session and navigating to the external hard drive and seeing what occupancy there actually is, but I am finding it easy to imagine but dificult to execute. For instance in windows disks have a letter identifying them, and if my external HDD were X:\ I would just write X: and I would be there. This does not seem available in Linux

So briefly
1. My actual problem is some kind of mis-reported disk occupancy
2. My handicap to self help is not being able to navigate to the disk in the terminal window

I would appreciate your help on both issues. I recognise that Linux is the better operating system, but it seems to me that the windows command prompt is more intuitive to use and navigate round the file system. But that may be just that I am used to it through work, though I gave up on Windows at home years ago.