Deletion of Files on USB Stick not always Clearing Space

[ian_r_h]

Hi, all,

I feel fairly confident with Linux now that I can research this problem on my own, but may still need to ask for help.  That said, I do have a work-around.  I post this for now in case anyone else has the same problem.

• Description:  On inserting (mounting) a USB stick, sometimes there appears to be (significantly) less space than ought to be available.  Note:  This is not the usual case of a USB stick having a little less space than advertized.  On deleting existing files, the USB stick does not show any additional space.  Operation so far only tested on Thunar (the file manager); not tested yet using the terminal.  File system is FAT-32.
  
• Hardware (laptop):  Only seems to be happening on one of my two otherwise identical laptops.  Possible hardware fault?
  
• Hardware (USB stick):  Kingston DataTraveller G4 16Gb (rated as Linux-compatible).  FAT-32.
  
• Software (file manager):  Thunar 1.6.11
  
• Linux Kernel:  4.4.0-110-generic (LL 3.6 64bit).
  
• Hypothesis:  Due to an as yet unknown cause, although the files are removed from the list, the space is not being freed up on the USB stick.  As a result, repeated deletion is resulting is ever-decreasing available space for file storage.
  
• Work-around:  Carefully reformat the USB stick using GParted (Menu/System/Partition Drives).  Carefully, because you don't want to format your hard drive or partitions!  Unmounting and re-formatting USB stick (to FAT-32 again) frees up the space.  Again, not tested formatting from terminal.
  

Two other common faults have been identified on this specific laptop's USB ports with this make and model of USB stick (for completeness):-

• As reported previously, Linux doesn't appear to like any USB extension cable I have tried (be aware).  Work-around:  Don't use USB extension cables!
  
• When mounting a Kanguru Flashtrust USB3.0 SecureFirmware USB stick (8Gb), USB sticks mounted afterwards report read-only until fresh boot.  (This happens in Thunar; but also the default file manager in Ubuntu/Unity.)  Work-around:  Reboot!
  

[justme2]

[member=7114]ian_r_h[/member]  I have no answer to your problem, just to say that I use USB extension cables with linux systems and no problems. There are different types of cable though, some are just a recharging cable for phones/tablets, some long extension cables have a built-in usb hub to act as a repeater and others have the standard five straight wire connections(+, -, D1, D2, gnd).
Standard cables work fine for me - my usb sticks are too wide to sit side by side in adjacent sockets, so cables are a must. Note: only able to test on USB2, I have no USB3 ports.

[bitsnpcs]

I had problems with Sandisk 16GB being read only, and also needed reboot to solve it.
It only happened 1 time on 1 of them so far.
I got it 3 for £10 from Tesco.

Kingston Datatraveller I have some of this 8Gb ones, x1 metal champagne one, and x6 flip ones red, none of these have had any issues at all. I don't have/and haven't used any 16GB Kingston.

Others I use now some micro drive 16GB, (no branding), it had no problems for me.

I used a 10 metres usb lead with boost as per the criteria of USB format, it worked fast and no problems on everything I used it with.
I use x6 extension of usb from 2 of usb switchbox to Linux Lite computers, well there is 8 of them but only using 6 now.
I use 1 extension of usb from mouse to switchbox.
I have the usb vertical pod the usb goes into it vertically, it has wired usb extension, I won it as part of wardriving kit before, it works correctly on Linux Lite, all that kit does.
Other I used splice, usb mini and usb micro > usb extension, charging and bi directional data, it works correctly on Linux Lite for me.
Other I used data link ups to usb , its from digital multimeter into usb etc.

Also I used many times male to female 2metres and also joining this 2 +1 metres extension usb cables.

[richtea]

[ On inserting (mounting) a USB stick, sometimes there appears to be (significantly) less space than ought to be available.]

Might this resolve the issue?


https://www.wikihow.com/Restore-or-Delet...%22-Folder

[ian_r_h]

Thanks to everyone.

About 1/2 hour after I wrote the post I thought, "Hmmm... I wonder if (unlike Windows) Linux places files when pressing the delete key into a trash?"  Looks like I needed to write the post to clear my head.

So,

1)  On the post subject:  Linux places files into a (hidden) trash folder when pressing [DELETE].  You need to empty the trash to actually free the space; or right-click and select the Delete option and confirm permanent deletion.  So that's that solved!

2)  I guess some extension cables work and some don't?  Not a major issue for me, personally.

3)  The issue of USB sticks suddenly appearing to go read-only looks like it's been around since at least 2014 in Ubuntu.  I originally came across the problem on Ubuntu/Unity with the default file manager.  No-one seemed to have found a definitive answer as to how to solve this; possibly because no-one appeared to have established exactly why it was happening.  I only use two makes-and-models of USB stick with Linux (as mentioned in my opening post).  I can confirm that whenever I use a Kanguru USB stick, Thunar (and the Unity file manager) will claim the Kingston USB sticks are read-only until a new boot.  I don't know enough to go much further with that at the moment; and rebooting after using the Kanguru stick always solves the issue.

[bitsnpcs]

Hello ian_r_h,

an interesting thread.
It seems to affect multiple brands of usb stick.

[TheDead]

I think some configuration see the USB key has a full fledge Hard Drive and treat it as such (i.e. non-removable). Also had the same on "another OS" sometimes.
I usually just reformat/wipe these USB keys. On Macs, on bad ejects this can be awful and lock drive/crash OS.
Also, some USB3 keys in USB2/USB1 ports give all sorts of problems.

BTW, you need USB3 cable extensions if you have USB3 keys and ports. Otherwise, it will run at USB2/USB1 speed, or, I'm just guessing give other problems.

Cheers!

[ian_r_h]

At some point I will need to return to the USB sticks going read-only problem.  This may be more useful generally once I am more familiar with Linux and esp. the terminal.  I only use two brands of USB stick, so that makes it possible to simply control the variables in my case, so it may present an opportunity to investigate the problem for a more general audience too.  Maybe.

Anyway, if I remember, I'll add a link to the dedicated thread at the end of this one, once I am ready to begin...