I am using ubuntu 10.04 x86_64. I'm having a certain problem while copying from my internal HDD (ext4) to usb stick (fat32). At first I get a fair speed (15-20MB/s) for the first half of the file and then it slows down but not significantly or in an annoying way...
The actual problem and my question is that when file transfer window informs me that 100% has been transfered and 0 seconds remain, the window remains there for about 30 seconds, depending on the size of the file, and it won't let me safely remove my usb stick when i try to. I also realized that when copying multiple files, copying is paused after each file being copied. For example, if I try to copy three files 100 MB each, so 300MB max, I get the first 100MB transfered normally (as the window informs me) then a pause like nothing is going on, after approximately 20-30 seconds it continues normally to second file, pause after that and finally i get the third copied and pause again, before the nautilus window with the transfer bar goes away.
System is fully functional during this time but it seems to me that a task is being done to the background, like OS is verifying copied data, or something like that, because the time of this pause varies according to filesize.
I've been using same usb flash drives with several OS, including previous ubuntu releases, on same machine, so I think it's not hardware problem. I also believe that it's not the effect from caching files before actually copy them to unit, as I don't encounter same behavior to other external storage devices.
Seeing the same behaviour here.
Linux WA12-L17234-linux 2.6.32-25-generic #45-Ubuntu SMP Sat Oct 16 19:52:42 UTC 2010 x86_64 GNU/Linux