Hard disk on USB slowed down

[wpte]

Maybe I discovered something. After my e2fsck check, the dialog said that there is a 36% non-continuous files.

Maybe this is why the file system is too slow. But how it happened? I never see this fragmentation on Ext3 filesystem

Is it possible to defragment it somehow???

It is... with some special expensive tools that are most likely going to break your partition
Best chance you have is deleting and placing back a lot of small files, since EXT3 is self-defragmentating as new files are being written.
36% sounds quite ugly tho

some reading material:
http://ubuntuforums.org/showthread.php?t=712384
http://geekblog.oneandoneis2.org/ind..._defragmenting
http://ubuntuforums.org/showthread.php?t=407889
http://www.dslreports.com/forum/remark,18125810

edit: as you can read in the last link, pyfragtools is free:
http://ubuntuforums.org/showthread.php?t=169551