Specific type of flash drive blocked or ignored by Sierra

Zimbop

Registered
I've had a problem with a specific type of flash drive in the past that did something such as connect/disconnect rapidly and seems to have led to a situation where that brand of USB stick is ignored now by MacOS Sierra (they probably all identify themselves to the system with the same name for example). I have tested the flash drives on another mac and they all show up normally.

Is there some sort of file on the system that logs these "ignored" drives, that I can reset?
 
You have to drop you old habits that older Windows systems allowed this very pull it of mounted drives! However Mac OS is based on BSD Unix called it Darwin.

So on you Mac (without the drive plugged into the Mac) just Reset your PRAM to fix the problem! Then don’t ever just pull out a mounted drive is not good! So first just drag the mounted drive to your Trash Can and it wil unmounted the drive to disconnect the flash drive!
 
Thanks but that's nothing to do with it. I only have a problem with Toshiba flash drives. I had one that had power drain issues or something, and subsequently the system has decided to ignore them. I haven't used windows since Windows 3.1.
 
When you pull the flash drive out without dragging it to the trash or clicking on the eject arrow from a finder window, you risk damaging not only the files on it but the drive itself.
You said you can successfully mount it on a different Mac. Is that a Mac that is running Sierra or a different OS version? Do you have files on the drive that you need? If not, use Disk Utility on the different Mac to do a repair and/or erase and format. That just may save the flash drive from the garbage bin.
 
Just to clarify, I have 5 brand new flash drives that aren't identified (are ignored). This is, I believe, because one of the same brand misbehaved to such an extent (mounting and unmounting itself rapidly due to power issues) that something about this type of drive is "flagged" by the system. The load and show up immediately on another Sierra based system.

The issue is, I believe, that this brand of drive has been blacklisted somewhere and flagged to be "ignored" because the system rather simplistically believes them to be that faulty drive.
 
First, check the packaging. Does it say it is for both Windows & Mac? What Mac OS version does it list?
Second, did you purchase these from the same store? Take them back for a full refund as they are faulty.

If you believe that it is the band, then avoid it like the plague. I haven’t experienced problems with any one brand in recent years.
 
Hi Cheryl. This is nothing to do with the brand. This is to do with a specific USB flash drive that had an issue being flagged on the system to be ignored, that now means that others of the same type don't load (are ignored). I just want to know where that type of blacklist/log would be kept so I can clear it.
 
Just to clarify, I have 5 brand new flash drives that aren't identified (are ignored). This is, I believe, because one of the same brand misbehaved to such an extent (mounting and unmounting itself rapidly due to power issues) that something about this type of drive is "flagged" by the system. The load and show up immediately on another Sierra based system.

The issue is, I believe, that this brand of drive has been blacklisted somewhere and flagged to be "ignored" because the system rather simplistically believes them to be that faulty drive.
You did say that only one brand seemed to be the culprit, yet you then state in your last post that it has nothing to do with brand...

Anyway, you are likely right, and it's simply the drive type. There's nowhere in the system, AFAIK, that would somehow "blacklist" specific types of storage, and I suggest that this would be a waste of your time to look. Even if it were in the system somewhere, all you need to do would be to erase the culprits, using Disk Utility while booted to your recovery system. That is usually a good first step, when using flash drives that probably come new formatted as either fat32, or large thumb drives might even come formatted NTFS, which your usual macOS system will read but not write.
Give that a try: Boot to your recovery system, and try to erase/format one of those flash drives. Changing the format to Mac OS Extended (journaled) would be a good choice, assuming that you would be using the flash drive only on a Mac.
 
None of these new flash drives can be seen by Disk Utility on my system. They are being blocked/blacklisted/denied at a much deeper level.

Anyway, please follow my logic. What I *originally* experienced was a flash drive that faulty. It mounted and unmounted so fast that some part of the operating system decided to isolate it. I did get some error message at the time (and oh boy do I wish I'd written it down) that suggested something about the device would be ignored, clearly some sort of USB protection. Consequently, these newer drives of the same type (issued by a company I work for) are being ignored not because they are faulty (they work on all other machines) but obviously because my mac thinks that these are the faulty one. In the respect it's brand related I suppose, but only because something about them (USB vendor ID date or some weird meta-data) means the OS thinks they are the faulty one.

I think this question can only be answered by someone who is familiar with the USB subsystem error handling. I'd like to just clear the error so I can carry on using the flash drive brand/type that my company issues!

Anyway, it's not a problem that people think I should just format them, it's just not the answer. This is just some long, much more boring technical issue than normal. Someone knows the answer off the top of their head and hopefully someone like that might chime in some time.
 
I respectfully disagree! If you can format the USB drive, then it should work for anything else when you need that flash drive.

Just so you know - if there is a hardware block on a USB port, that is released completely by performing a power cycle.
I define a power cycle as power off (not just a restart), then boot as normal.

So, did you try Disk Utility while booted to your recovery system?
The reason that I suggested the Recovery system, is that does not use your system to boot, only that system image that is kept in the recovery partition.
So, any software setting stored in your system would not be relevant when you boot to the recovery system.
Also, if there is something stored in hardware, a PRAM/NVRAM reset will reset that, too, so try that as part of your steps. Let the system reset a minimum of 3 times before you release the key.

Just so we are "on the same page", boot to the recovery system by restarting, holding Command-R
You will boot to a menu screen, with Disk Utility as one of the choices. This is NOT your normal system, and won't boot to your normal desktop. Run Disk Utility from that menu, while your suspect flash drive is attached.

If that does not seem to work, you can also try booting to Internet Recovery, which is similar, but boot to that while holding Option-Command-R.
Internet recovery boots your Mac through your internet connection, using Apple's servers, and does not use your local system software at all.

If all still fails, and that suspect flash drive is not recognized by any USB port (be sure to try each port, restarting between each test, then double check each port with a USB device that you KNOW works, making sure it still works on your MBPro.

Finally --- be sure to run your diagnostics to see if any errors are reported from that.
 
Hi thanks for this.

Note that I can use other flash drives and peripherals – this isn't a particular port that has an issue. Also, I don't need to reformat these drives as they work on other macs and need to be formatted Fat32 anyway, which they are already.

I'll try the recovery partition when I have a moment. I'm not averse to it, I just can't at the moment. I'm at an absolutely critical point in a project so don't want to go zapping any pram until I'm clear, but very grateful for all contributions, agreeing or disagreeing :)

I'm also somewhat aware that while I'd really like this fixed, I'm probably too busy and distracted to have done a really good, clear write up of this issue. Apologies for that. I'll try and be a bit more thorough and succinct when the current crises are over!
 
As a Mac user you have to realize that most of the world is Microsoft world in the manufacturing processes! So as Mac user you have to FOMAT any drive you buy to be read/write for Mac OS. So did you first format that drive?

Plus Reset the NVRAM or PRAM on Your Mac is easy and it has been known it can resetUSB/FireWire/Ports on a Mac by resetting that small chip!
 
As a Mac user you have to realize that most of the world is Microsoft world in the manufacturing processes! So as Mac user you have to FO(R)MAT any drive you buy to be read/write for Mac OS. So did you first format that drive?

Plus Reset the NVRAM or PRAM on Your Mac is easy and it has been known it can resetUSB/FireWire/Ports on a Mac by resetting that small chip!
That's a bit of misinformation. Most flash drives will come out the package formatted as fat, and should work without any change on most any OS.
If you don't need to use the flash drive on Windows, or some other non-Mac OS, then formatting for Mac OS Extended (HFS+) is a good plan, but shouldn't really be necessary --- and other users don't have to do what you (or I) would do with an out-of-the-box flash drive.

However - OP apparently needs to have a Fat-format for use in other computers, so that should also work in a Mac without further prep.

(I suspect that there may be security software, maybe for file encryption, like some flash drives are sold, and the system on the OPs home Mac does not like that software on the drive, for some reason. It's another reason to try formatting the flash drive on a Mac, as that would tell you several things, number one being that the flash drive can stay mounted long enough to do the format, so there is nothing physically wrong with either the flash drive, and (probably) nothing wrong with the USB bus on that home Mac. Doing the while booted to the Recovery system will eliminate some setting in the system that might be preventing the use of those flash drives.
 
I think you need to reinstall your USB controllers, because this might be the problem why your USB device is not recognized, so try to reset your USB port. Another thing is, maybe your PC requires an update for issues that conflicts the USB external hard drive. Just check, if it's missing other important hardware or software updates. Hope this might help you!
 
I think you need to reinstall your USB controllers, because this might be the problem why your USB device is not recognized, so try to reset your USB port. Another thing is, maybe your PC requires an update for issues that conflicts the USB external hard drive. Just check, if it's missing other important hardware or software updates. Hope this might help you!

Mac OS does not have individual USB controllers to install. Mac OS does not have a reset for the USB port unless you mean shut down (not restart), then start up. Unless you are more savvy (and I am totally wrong), in which case, can you give a step by step for reseting the USB port?
 
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