File Size Or File Count Limit?

[PGB1213]

Hi All!
I'm not sure this is the correct place on the forum to post this, so please pardon my error if it is in the wrong spot.

I have a 32 GB SD card in my ZTE Maven Z-812 phone running Android 5.1
It has just under 4GB Of data on it. (28+ GB Free)

I tried moving some music files to the SD using Android File Transfer. The albums show as folders. The window shows that all moved, but in actuality only the first 2.26 GB moved. The count is 31 folders.

Next, I removed the SD and connected it to the computer & tired again. Exactly the same 2.26 GB moved. Nothing else moved. Oddly the window showed the folders, but all after the first 2.26 GB were empty. Upon eject & re-insert, the empty ones were gone. The file count again were 31 folders.

I thought I'd be smart and make a second Music folder, calling it "Music 2", but the music app can't find it.

Is there a folder size limit with Android? Perhaps a folder count limit inside a folder?
Or, Heaven forbid, is my SD card perhaps wonky & in need of replacement?

Thanks Very Much for your advice. It is much appreciated!
Enjoy This Day!
Paul

 

[Dannydet]

I'd question the SD card as I've copied many music folders without an issue

 

[svim]

I'm going to go with the problem being either the microSD card as a possible, and the USB cable or some other USB related issue as the a probable.
The ext4 file system, what the internal storage in your Android device is using, is a pretty robust file system. The maximum number of files will be based on the capacity of the storage media itself, but the 'maximum' maximum tops off at 4 billion or so.
https://en.wikipedia.org/wiki/Ext4

Have you tried using a different USB cable? Or if you're plugging it into a USB hub, try using a USB port on your computer instead. If your PC is running Windows, try reinstalling the USB driver:
https://www.zteusbdrivers.com/2018/02/download-zte-usb-driver-2018-for-windows.html

Another option is to try using the AirDroid app, it relies on WiFi connectivity so no USB cable is necessary. All you need is the app running on your phone and then you use the web browser on your computer to network the two together.
https://play.google.com/store/apps/details?id=com.sand.airdroid&hl=en_US
Or try removing the microSD card from your phone and mount the card directly into your computer and see if the same problem occurs. If it does that might be a sign the card might be failing (or possibly just needs to be reformatted but that's a big if), if there isn't any problem copying files back and forth that indicates it could be a USB cable or USB issue to look into more.

 

[PGB1213]

Thank You DannyDet & Svim for taking time to reply with helpful suggestions. I very much appreciate your help.

Since you explained the file size being pretty much unrestricted, Svim, I ruled that hypothesis out. That was an interesting article you linked.

I tried a coupled of USB cords, directly into the computer, that you mentioned Svim. Unfortunately, the problem remained.
Next I tried putting the SD directly into the computer & moving files there. Then, I moved files one-by-one. It showed all files moved on the computer (Mac), but many folders were empty. Oddly, 31 Files again & 2.26 GB again. It is almost like the SD said 'I Quit".

I didn't have luck connecting with Air Droid, but will try again later. It may be my computer or the phone. The app looks very, very handy to have on the phone.

At this point, I think I'll have to get another SD card for the phone. If the problem is solved, I'll junk the existing one. If not, I'll have a spare- but will still have a problem to solve. (I suppose after that I will try restoring the phone to factory. Next would be to suspect a problem with the SD slot.)

Thank You Both Again! I sure appreciate your help and the education, plus helpful suggestions.
Enjoy Today!
Paul

 

[svim]

Just to add to the confusion, there's the added problem that affects microSD cards in general. The internal storage in your Android phone uses ext4 as its default file system, which even though is pretty dated now is still quite adequate. A typical microSD card however will be using either FAT32 or exFAT as its default file system, the issue being Microsoft finagled its FAT file system to be become the default USB storage file system years ago and we're all still living in that plague, as FAT was only a marginally functional file system even back in its day. Fast forward to today and FAT file systems have serious problems with current standards -- file metadata support is weak and file/folder permissions that modern day operating systems use are barely supported. Add in that FAT is proprietary and any development resources were cut off over a decade ago. The basic problem is FAT32/exFAT are still applied to SD cards so they remain 'universally' compatible with multiple operating system platforms -- you can conveniently mount a card in a Linux, a Windows, or a Mac computer and use it to transfer files. It's not optimal but companies like Microsoft and Apple are fiercely protective of their products so MS won't allow other platforms use NTFS, nor will Apple allow other platforms to use HFS+/APFS, nor will either platform include support for open source file systems like ext (at least by default, you can can use third-party utilities to add ext4 support but YMMV.)

All that said, a simpler statement is microSD cards are about convenience and not necessarily practical. When you're transferring files from your microSD card, if you're doing so using a file manager app on your phone (natively), or using Windows Explorer or Mac's Finder (remotely) there's always going to be workarounds involved (at a deeper level than what we see in any GUI interface). When you mounted that card into your Mac and don't appear to see everything on the card that would indicate the card is the problem. When the card is in your phone, if you go into your Settings >> Storage menu can you see all the files and folders from there?

 

[PGB1213]

Thanks Svim for your excellent explanation of the various file structure choices. I thought that I'd heard of them all, but ext4 is a new one to me.

When the card is in your phone, if you go into your Settings >> Storage menu can you see all the files and folders from there?
Nope. When I go to Settings-Storage all that shows up for the SD is "Total Space" and "Available". Tapping either doesn't open a new window.

If I go to File Manager application on the phone & choose SD, the Music folder is not the same as what I see on the computer when the SD is in the USB port. The empty folders do nor appear in File Manager, but do appear on the computer screen. File Manager also does not show the loose songs. Unfortunately, the SD does not appear as a drive in Mac OS X, so I have to use a helper app, such as Android File Transfer instead of Mac's Finder. I don't know if that Android File Transfer application is giving accurate results or not.

In Settings - Storage, for Phone I get "Available", "System Memory" and "Used Space". Tapping "Used Space" brings up a list of some, but not all, of the folders I see in File Manager app. One can tap any of those & most bring up either a file list, or Gallery.

Android sure is complicated as far as navigating file system is concerned, at least compared to Mac OS X. But, I'm learning!

 

[svim]

Something to keep in mind is when you're using something like a file manager app on your phone or the Settings >> Storage menu those are running locally and are native (Android OS), but when you're viewing your Android phone from your Mac computer it's a matter of doing so remotely and using a non-native OS (Mac). A lot of people harp on Android being based on Linux and Macs being based on BSD, both Linux and BSD being offshoots of Unix, but once you actually take the time to directly compare each of them as far as file structure there are obvious similarities but are in fact altered quite a bit from each other. (... the degree as to how much being debatable.) Here's an example of what Unix is set up as:
https://en.wikipedia.org/wiki/Unix_filesystem#Conventional_directory_layout
You're probably more familiar with how your Mac is set up to use:
https://www.dummies.com/computers/macs/mac-operating-systems/basics-of-the-os-x-folder-structure/
Compare those to a typical Android device:
https://www.androidauthority.com/phone-storage-folders-explained-744100/
So it's not so much that the Android file structure is more complicated, it's just different from your Mac. Once you get past that unavoidable familiarization phase it won't be such a mystery when things don't show up where you expect them to on your phone (especially when it comes to how you're viewing things -- locally or remotely using a different operating system). Another big factor that can't be discounted unless you've rooted your Android device, there are going to be a lot of files and folders you simply don't have access to. With your Mac you most likely have admin privileges when you need them, with your phone it's a different matter. It's one thing to be able to access system-level files when rooted, but when you're not it's just a matter of working with the files and folders you do have complete (... also keep in mind that being able to view some otherwise restricted files/folders won't necessarily mean that you have the ability to manipulate them too -- i.e. rename or alter their contents, but whatever the case you might find it helpful to enable any option in a utility you're using to show hidden files. The file manager app it'll be in the app's Settings menu, in the Mac Finder - using Command - Shift - period to toggle on/off).

 

[PGB1213]

Thank You Again Svim for taking lots of your time to explain and educate! I've found your explanations very interesting, indeed.

I learned a lot from the articles you linked. As you mentioned, I was somewhat familiar with OS X file structure and knew the basics of Unix. But Android was a mystery to me- so much of a mystery that I was afraid to explore too deeply for fear of wrecking something.

Your explanation of how Android is not more complicated, just different puts everything into clear perspective. One would think, since I have worked with Mac, Windows, DOS and a little Unix that I would have realized that Android is "simply different". (Now that I've read your linked article, the Android file system structure makes a whole lot more sense to me than Windows ever did. But DOS still is my favorite file structure.)

Actually, before the SD card problems, I had been having phone booting trouble and had to do a factory reset. Before I nuked the phone, I dived (dove?) deeper into the file system than I have in the past. (There was nothing to lose at that point.) The exploring was interesting.

Of course, some of my applications don't store things where I would expect (Example = Camera ignores DCIM and goes to Pictures). I was also surprised to see apps that I moved to SD have files on the phone storage as well. The small ones I attribute to the app's "get going" files, but the larges ones are a mystery.

Thank You Again. I sure learned a lot from your posts. And thanks DannyDet for your thoughts on the SD card. (You were right, it is intermittently bad, as tested with read-write cycles on the computer.)

When I get brave enough, perhaps I'll try a root to get rid of the AT&T apps that don't work, but track anyway. (Not to mention run in the background whether started or not, like Hot Spots.) I'll also be happy to be able to delete the ZTE apps that also don't work. (Disabling does not stop AT&T or ZTE apps. I guess they own the phone, not me.)

Enjoy This Day!
Paul