Connect to Folder problems

[DMcCunney]

Calibre and my master library live on an HP quad core desktop box running a current Win10 Pro release.

My primary eBook viewer device is a 7" Android tablet running Android 4.4 Kit-Kat with FBReader as the eBook viewer software. Books reside on a 32GB microSD card in the deivice.

MTP is a non-starter on the device, so the best way to update the on device library is to shut down the tablet, pop the microSD card, put it into an adapter, and plug it into a USB port on the desktop, then use Connect to Folder to access it.

This worked yesterday, and fails today. The adapter can be plugged in to a variety of ports on the desktop. There are front facing USB2 ports, 4 port and 7 USB2 hubs in rear-facing ports, and rear facing USB3 ports provided by a USB3 PCI-e card. (The HP did not come with USB3 on board.) The 4 port hub connects my keyboard and mouse. The 7 port hub holds an assortment of thumb drives.

I can plug the adapter into any USB motherboard port or the 7 port hub. Win10 will see it, and it will appear as drive N:. I can drill down into it in Windows Explorer, and run CHKDSK which it passes with flying colors.

If I run Calibre and say Connect to Folder with that device plugged in, Calibre hangs and must be killed. I must reboot the machine to get Calibre to Connect to Folder on a local drive once this has occurred.

This worked yesterday. It fails today. I have changed the adapter the microSD card is in, tried plugging it into motherboard and hub USB ports, and moved the 7 port USB hub to a USB3 port provided by the add on USB3 card. It doesn't matter. Calibre hangs doing a Connect to Folder if that drive us plugged in. (I also installed a new Calibre point release while trying to resolve this with no difference in behavior.)

Can anyone suggest a way to debug what is occurring? There have been no significant changes on the desktop or tablet sides between it working yesterday and failing now, so I'm scratching my head in confusion.

Thanks in advance.
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Dennis

[theducks]

Leave calibre out of the picture for this.

Use the disk tools to check the SDcard for errors.
In explorer right click the drive letter:properties: select the Tools tab: check:scan and repair drive

Once passed: try and use the OS to copy a Book or TXT file to the SDcard
Now open the file (right click: Open with: <your fav for that type>

Now we are ready for Calibre

[DMcCunney]

Originally Posted by theducks

Leave calibre out of the picture for this.

Use the disk tools to check the SDcard for errors.
In explorer right click the drive letterroperties: select the Tools tab: check:scan and repair drive

Please note I stated that it passed CHKDSK with flying colors, and that it could be accessed from Windows with no issues.

This does not look like a problem with the card.

Once passed: try and use the OS to copy a Book or TXT file to the SDcard
Now open the file (right click: Open with: <your fav for that type>

Already did. Worked fine.

Now we are ready for Calibre

Which brings us back to my original question. Calibre doesn't like it. Why not? How do I find out?
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Dennis

[kovidgoyal]

It is a problem with the Sd card, SD card's are notoriously unreliable. calibre will have to scan all the files on the card to search for books, and read metadata from those files, which puts a lot more strain on it than simply opening it in windows explorer or similar. To test that for yourself simply copy the contents of the card onto an internal disk and try using connect to folder with that.

[DMcCunney]

Originally Posted by kovidgoyal

It is a problem with the Sd card, SD card's are notoriously unreliable. calibre will have to scan all the files on the card to search for books, and read metadata from those files, which puts a lot more strain on it than simply opening it in windows explorer or similar. To test that for yourself simply copy the contents of the card onto an internal disk and try using connect to folder with that.

I'd ordinarily agree, but I just tried an experiment.

The Calibre version on the desktop is the current 64bit release. But I also have the current 32bit Calibre Portable release installed on a thumbdrive.

I put the microSD card into the adapter and plugged it into the desktop. As before, Win10 could see it, assigned drive letter N:, and would let me run a file systems check reporting no errors, and drill down onto the card and see the directory structure and files.

I ran the portable version on the desktop from the thumbdrive. I pointed it at the master Calibre library on the desktop, and at the folder to connect to on the microSD card.

Calibre Portable has no problem with the card, successfully inventoried the contents, and I'm in it now transferring files.

If this was an SD card problem, I would expect Calibre Portable to have the same problems as the desktop version.

I'd still love to know what the desktop version's problem is, and suggestions on debugging will be gratefully accepted.
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Dennis

[kovidgoyal]

There are zero differences between portable and desktop versions when it comes to scanning filesystems, they both use the same underlying OS APIs. If you are noticing a difference, then it is because something on your system is interfering with the 64bit application but not the 32bit one. Try turning off your A/V which is the most liekly culprit for this kind of thing.

[DMcCunney]

Originally Posted by kovidgoyal

There are zero differences between portable and desktop versions when it comes to scanning filesystems, they both use the same underlying OS APIs. If you are noticing a difference, then it is because something on your system is interfering with the 64bit application but not the 32bit one. Try turning off your A/V which is the most liekly culprit for this kind of thing.

I don't use third-party A/V. Windows Defender is entirely adequate. (And if it was A/V getting in the way, I'd expect that to bite the portable version of Calibre too. For that matter, I'd expect A/V to throw up a screen telling me it blocked access.)

I assumed there were no differences between the portable and desktop versions beyond 32 bit vs 64 bit.

This worked yesterday. It fails today. There have been no changes on the system that would account for it.

Something is obviously blocking the 64bit version's access to the card. I'm trying to discover what it is.
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Dennis

[kovidgoyal]

You can run calibre in debug mode (right click preferences button and choose restart in debug mode) that will give you more verbose output about what calibre is doing.

[DMcCunney]

Originally Posted by kovidgoyal

You can run calibre in debug mode (right click preferences button and choose restart in debug mode) that will give you more verbose output about what calibre is doing.

That was the hint I was looking for. I'll try that over the next day or so.

Thanks!
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Dennis

[AnotherCat]

I don't know what the cause of your problem is but the first thing I would likely do if I encountered it would be to remove the adapter from the port then, in Windows, go to Device Manager>View>select "Show hidden devices". If the adapter is then shown under Disk drives (it should be even though it is not plugged in) then uninstall it.

Plug the adapter in and let it reinstall itself (I would likely reboot the PC before doing so, though that for probably no particular reason).

I know that sounds of little chance of solving the issue given that Windows itself can see the device, but given it only takes a minute to try it is what I would try first.

[DNSB]

Originally Posted by AnotherCat

I don't know what the cause of your problem is but the first thing I would likely do if I encountered it would be to remove the adapter from the port then, in Windows, go to Device Manager>View>select "Show hidden devices". If the adapter is then shown under Disk drives (it should be even though it is not plugged in) then uninstall it.

Plug the adapter in and let it reinstall itself (I would likely reboot the PC before doing so, though that for probably no particular reason).

I know that sounds of little chance of solving the issue given that Windows itself can see the device, but given it only takes a minute to try it is what I would try first.

Actually show hidden devices won't work for non-present devices. I use the following lines in a batch file which needs a right click and run as administrator to show non-present devices.

set devmgr_show_nonpresent_devices=1
cd \windows\System32
start devmgmt.msc

An alternative is to use Nirsoft's USBDeview, again right click and run as administrator to allow deleting devices.

[AnotherCat]

Originally Posted by DNSB

Actually show hidden devices won't work for non-present devices...

It works with Windows 10 Pro on every PC that we have so I am not sure why you do not see them. Previously used but not currently present USB drives show.

For example, on this machine I am using right now the current list shows a fleet of USB drives, spinning and flash, not used in the current session nor indeed in any previous session for some time.

It may be that other non drive USB device types may not show but among those we use I have not come across any (not that I go looking for them ); for example we use a number of RS232 to USB converters and they are currently not present on this machine but are showing as hidden serial ports - in fact each device shows multiple times, each instance being for the various COMx that have been associated with it in different sessions.

[AnotherCat]

Just checked this hidden device thing out.

As default Windows 8 and 10 should show hidden devices even if not present. As said, they show here, no problem.

In Windows 7 and earlier one has to set devmgr_show_nonpresent_devices=1 to enable as you have done.

OP states they are a Win 10 Pro user.

EDIT: I have now hunted down the Microsoft Support for it - https://support.microsoft.com/en-nz/...-not-connected . Note also that in Win 7 and earlier it seems that the CMD is reset on closing.