Officially, you’re supposed to click on program which disconnects it, but sometimes that doesn’t let me do it (typically claiming that it’s in use even though it’s not AFAICT), and sometimes I just yank it out anyway. I’ve never noticed anything amiss with either the computer or flashdrive as a result, but perhaps I’ve not noticed something and/or been lucky.
Bottom line question is: how big of a deal is this, what could go wrong, and how likely is that to happen?
If you yank it out when it is writing to the drive you could mess up the file allocation table of the file system. Or the file itself would be half written and be corrupt. This is more likely to happen with a large file such as a video file.
It does depend on the file system in use and the application doing the writing. Some are more robust than others. It is best to apply the precautionary principle and eject the drive gracefully, just in case.
The requirement to eject is mostly historical, but getting the user to stop and think about removing the drive also serves some purpose.
In general, it doesn’t matter. Windows (assuming that’s what you’re using) knows it’s dealing with a removable flash drive, so it doesn’t delay writes as it would on some other disk.
It is possible for an application to crash if the drive it’s accessing is removed. Normally, a modern application will write a file to disk (or read a file from disk) for a small fraction of a second, immediately when the user does an action (clicks Save, etc.), and then be done with it. Timing-wise, it’s very unlikely that the (same) user will pull the drive out while this takes place.
But pre-2016 versions of Word or Excel were more greedy in this regard, they would lock the file and sit on it, and create a temp file next to it, as long as it was open on screen. Getting users to close those applications would keep those applications sane and limit left-over temp files on the drive.
It may not delay writes, but if the file is not a Word file but a huge file that takes 10 seconds to write, and you pull the drive out after 5 seconds, it won’t all be there.
I have found that, most of the time, if it’s not letting me eject, it’s because I have an Explorer window looking at the drive.
Anyway, sounds like Windows has gotten smarter about never buffering files that are supposed to get written to external drive, so you’re probably OK as long as it’s not currently being written to. I would still try and eject safely, though.
The problem is that since drive activity lights have become much less common, even on flash drives, (I blame Apple), it is very difficult to know if a drive is being written to. Even then, if the light flashes occasionally, that may mean some write activity (don’t remove), or some read activity (safe to remove).
So, how bad is it to just yank out a flash drive? It is exactly as bad as the importance of the data on the drive.
Will it hurt the filesystem on the drive or the data to just yank it out? Only if files are actively being written, or need to be written. Do you know if files are actively being written or need to be written?
Will it hurt the drive itself? No, you can always just reformat it. If the drive is bad, it wasn’t because it was yanked out, but because flash memory and other chips can go bad, particularly on very cheap and abused things like flash drives.
How do I deal with it? If the data on the drive is important to me, and Windows refuses to eject it, I’ll perform a full shutdown before pulling the drive. If I plan to wipe the drive anyway, and Windows refuses to eject it, I’ll just yank it out.
I have had files get corrupted. What’s the hurry to wait for the eject?
The OP seems to be describing those many situations where Windows won’t let you eject it.
First, I suggest making sure you can’t find an app that might have it open and close that app, and try again. It’s still better to eject properly.
If that doesn’t work, then I’d normally say to just wait a few minutes until you’re sure there’s nothing being written to the drive, and pull it out.
However, if you want to be extra sure, you can always shut down your computer entirely before pulling out the drive. This is what I recommend when taking SD cards out of phones if “eject” doesn’t work. On computers, I would only do this if I really cared about the data.
I also note that, if you do pull it out early as per above, you can usually put it back in, check and make sure everything is okay, then properly eject.