Problems unmounting usb devices


when i connect external usb drives (mp3 player, hard drives, etc) and i browse with dopus, i very often cannot unmount the device, even if the last file access is many minutes ago.

of course i changed folders, such that no folder on the external device was open.

even closing dopus does not do the trick. i can only unmount if i also terminate the tray icon part of dopus.

this is very annoying.

anybody else having this problem?
i have it with many devices, so it is not a problem with a particular device.

any help is much appreciated.

I think for the most part this is Windows being in an "overly protective mother mode". The concept of the "Safely Remove Hardware" tool is a Microsoft effort to prevent possible file corruption or drive damage from occurring if a device is unplugged from a USB port during a file transfer process. The most likely scenario for that happening would be in a situation where the files are cached so the transfer may take several seconds, or even minutes longer to complete (as compared to non cached drives) depending upon the system configuration.

However as you have noticed DOpus seems to grab a USB connected device and holds onto it until the DOpus program has been completely exited. I'm not sure why there's not a DOpus time out on the non focused USB drives, but there doesn't seem to be.

None of that's an answer for you though. Here's what I do, and take this for what it's worth. After reading a number of articles that support this idea, I now just unplug my external hard drive, my external keyring flash drive, my digital camera, or whatever, once I know the file transfer is completed (which is easy to see when using DOpus). In other words, I never use the "Safely Remove Hardware" wizard at all. My Windows 2000 Pro machine throws a hissy fit when I do that, but I've never lost a file yet.


Hi John,

Interesting insight you have here.
I can add though that under Win98 SE I have no trouble at all adding or removing a Flash Card reader.
The additional drive letter is immediately displayed or removed.

I think this worked under Win XP as well, but I can't say for certain. My sister now has that homebuilt.

                                  Thanks John,
                                  Tsunami :opusicon:

Opus does seem to sometimes keep a lock on removable devices even when it isn't showing them.

I decided to try and narrow down the cause of the locks and it seems to me it's FlatView mode.

In my brief tests I first disabled all viewer plugins, in case one of them was responsible, then restarted Opus and mounted a USB CompactFlash reader.

I found that I can move around directories, copy, delete and view files and then still remove the device fine (provided I'm not still showing it in a lister, which is fair enough).

However, if I simply mount the CF reader, navigate to it, turn on FlatView (Grouped) and close the lister then the device cannot be removed until I quit Opus.

Does this tie in with what other people are experiencing or is it more complicated?

i think you're right. it is probably a caching issue.
but is m$ over-cautious here? i don't know. i had lot's of problems with usb devices (most noticably with hd-mp3-players and usb-hds), including data loss. (i am a professional software developer and i know and handle my tools well, so rule out mishandling.)
that's why i want to be on the safe side here...
i am doing what you describe, john. i simply unplug my devices after a while when i can be sure the os cache has been flushed.
however, in my opinion this could be an indicator that this particular part of the dopus code is not altogether "clean" and needs some improvement.

a hardly ever use the flatview mode. in my case this is certainly not the cause...

i will write an email to dopus support about this...

thanks for your considerations, folks!