flaky usb behavior

[GreyGeek]

Problem here is that I thought this flash drive was the Live Kubuntu flash drive, containing the iso, in which case there should be no partition per se. If you view it in gparted, it may say /dev/sdx, ISO9660 -- i.e., there will be no partition to put a boot flag on! And no boot flag is necessary, it's all coded into the iso image written to that flash drive.

Steve Riley and I got into a detailed discussion about this once:



So now if he writes an MBR to that flash drive, it will kill his live Kubuntu iso.

https://www.kubuntuforums.net/showth...l=1#post370675

I'm just saying what worked for me on my hardware. His mileage may vary.

[oldgeek]

Well, since this thread seems to have reached a dead end, I have decided to live with the problem. It's not much effort to plug in a 'dummy' usb in order to use the one I really want to use. Much less effort than to write to the forum, to be exact. But I really appreciate the response I got from members of this forum who tried to help, and in fact did help to put the problem in perspective. Not everything works right, but considering the complexity of the machines we use, it's amazing that they work as well as they do, and if they don't, that there are people who for no personal profit, are willing to spend their valuable time giving their expert advice in the hopes of helping a perfect stranger to solve his problems.

[Qqmike]

Not everything works right, but considering the complexity of the machines we use, it's amazing that they work as well as they do,

A good point I've often thought about. If you are driven to solve puzzles, one might obsessively pursue some of these small issues (that usually have a workaround). But unless you are the programmer, you really have very little ultimate control and shouldn't drive yourself nuts and should be grateful for how well these modern OSs work to help you work better and help you have some fun. If you want to deal with challenges that you do have control over, take up something like woodworking and strive to get your work on the 4-color-glossy cover of Fine Woodworking. A good philosophical point you make, oldgeek.

[oshunluvr]

I, for one, am stymied. I can't imagine why this is occurring unless the USB drive in question simply has something wrong with it. I'm no expert, but it seems the system, when you plug in a USB drive, detects the device. Then activates the device though use of a driver or drivers, and then you get access to it. Inserting a second device should have no impact at all on the first device, or vice-versa. So why is this happening?

[oshunluvr]

Ok, so I reviewed the entire thread. Only two things seem likely to me;

1. The drive has a bad controller: This would explain the odd behavior including the initial crash when trying to copy a large file to it. The controller on the device may be working in some ways but not others thus the wonky behavior.
2. The initial crash during the copy attempt was caused by an unrelated issue but left something behind that is blocking this particular drive. These drives all have "signatures" so the system can detect not only that you inserted the drive, but also it's brand, type, size, and a plethora of other device info. Maybe, since this crashed process was incomplete it's trying to do something with it when the drive is re-connected through UDEV or systemd.

Both of these theories can be tested.

1. If the drive behaves the same on another computer running a different OS, we know the drive itself is the problem.
2. If the drive works normally on another computer or on the same computer when booting to a different OS, then we know it's the OS causing the problem.

That's all I got.

The good news is name brand 16GB USB 2.0 drives cost less than $5 US and you can get a 32GB for like $9. All you gotta do is skip one beer and buy a new drive instead, so there's that.

[oldgeek]

Perhaps my posts weren't clear enough, but the problem is definitely not in the USB apparatus itself. I've tried various combinations with a number of different usb drives and there are three things in common: the first usb drive will not mount by itself, no matter who it is; the second drive inserted while the first one is still in always opens correctly--you can tell immediately because the bar graph of the content appears, and this behavior continues even after the first, unmounted usb is taken out; and while the next drive will open, a fourth drive will not. Nothing earth-shaking, but it's as if plugging the first drive in tells the program to mount the next one and not this one. Flaky--but it seems like some code has gone awry.

[oshunluvr]

OK, so it's not a specific USB drive that won't mount but none of them mount initially? Wow, that's even weirder.

Ok so it's a problem with the OS or the USB driver/USB firmware. Odd indeed.

[Qqmike]

Ok so it's a problem with the OS or the USB driver/USB firmware.

Yeah, but I don't have this problem in my 18.04.

So would there be any packages at fault here? Who knows. You can open Muon and search for usb and see what comes up. For me, not much came up except usbutils (and a couple others that don't sound relevant), and I'm not sure that's the one that manages device notifier events, but maybe it can be used to help diagnose? Without doing research, I don't know.

[oldgeek]

I checked out the usb utilities in Muon, but I have no idea what to do with the information. I suspect garbage somewhere as I went from Kubuntu 16.04 (upgraded, not a new install at that) to a Neon hybrid and then saved my concoction with Aptik before restoring it to my brand new already possibly corrupted Bionic Beaver. At the moment, it's not worth re-installing Kubuntu to fix what is an intriguing yet minor problem. Everything else works beautifully and that's what matters.

[Qqmike]

At the moment, it's not worth re-installing Kubuntu to fix what is an intriguing yet minor problem. Everything else works beautifully and that's what matters.

Makes sense.

I checked out the usb utilities in Muon, but I have no idea what to do with the information.

I checked in Muon, usbutil, Installed Files, and I see two possible commands: lsusb, and usb-devices (under user/bin). They do generate a lot of usb info. Not sure where all that leads.

[oldgeek]

So what is the driver for the usb thumbdrives? And how do you know if it's bad?

[Qqmike]

-->> Anyone else want to take a shot at this? I think we do have some experts experienced at this level.

I really don't understand it fully, especially without researching it. Those two commands (above in my post) do show something, as does K > System > Info Center > USB devices, and maybe the PCI's show something. I do, however, know how to put the PC desktop system hardware together and hook up the USB connectors .

[jglen490]

I'll let the RealExperts^TM chime in on that, but I've never had to manually mount a flash drive -- always just click on the device notifier, or maybe it was listed in Dolphin.

Which should be done under control of udev. Could it be that some rule file used by udev became corrupted when the the OP was doing what happened in the opening post of this thread. In my mind, a hardware problem (i.e., USB) is due to either bad hardware, incorrect firmware setting, or bad execution of some driver or management software. Since it is inconsistent or oddly conditional, it may be a udev procedure that has somehow become corrupted but is not completely missing. I'm not sure, but is it possible to re-install just udev?

[oldgeek]

Given the current political situation in Peru, I think corruption might well indeed be a likely cause!

[Qqmike]

Given the current political situation in Peru, I think corruption might well indeed be a likely cause!

Here in America, we only have fake corruption at the White House--it's not really real.