No UMS? Why? - Nexus 7 Q&A, Help & Troubleshooting

So, guys, just a quick question.
I know JB does not support UMS, but I can't figure out wjy.
Why would someone remove this feature?
Any suggestion on how to implement UMS in this great device?
Thanks

Use Stickmount?

nricci said:
I know JB does not support UMS, but I can't figure out why.
Why would someone remove this feature?
Click to expand...
Click to collapse
When you use UMS, the host machine is in charge of the filesystem. This means that Android would no longer be able to read and write to the partition while it was mounted. Because the sdcard partition in Android 4.x is a FuseFS partition; it is shared with data. This means that you won't run into the situation where you have "lots of space" but can't install applications -- the available space on your device is your available space for applications and any other data or media you want to store on your device. Because the sdcard partition cannot be mounted and unmounted, you can't use UMS.
MTP allows the device to keep the partition mounted and is an "application" on the device that knows how to show directory content, and to save or retrieve files over the USB. Given the design constraints, MTP gives the most flexibility and the best user experience with transfer rates being the most limiting factor.
Interestingly, MTP was also used for the Zune to give that device a way to index files as they were added to the device. This is why the Zune was able to search very quickly for albums, artists, and songs. Apple solved that problem in another way, by requiring iTunes, and letting iTunes build the database when you installed new media. Although slightly different than the question you asked, hopefully this gives you some insight as to why Jelly Bean doesn't have UMS... or more specifically the Android device you are using.
As far as I know, you can still support UMS with Jelly Bean device, but there are very good reasons why your Nexus 7 does not.
Sent from my Nexus 7 using xda app-developers app

Chinpokomon said:
When you use UMS, the host machine is in charge of the filesystem. This means that Android would no longer be able to read and write to the partition while it was mounted. Because the sdcard partition in Android 4.x is a FuseFS partition; it is shared with data. This means that you won't run into the situation where you have "lots of space" but can't install applications -- the available space on your device is your available space for applications and any other data or media you want to store on your device. Because the sdcard partition cannot be mounted and unmounted, you can't use UMS.
MTP allows the device to keep the partition mounted and is an "application" on the device that knows how to show directory content, and to save or retrieve files over the USB. Given the design constraints, MTP gives the most flexibility and the best user experience with transfer rates being the most limiting factor.
Interestingly, MTP was also used for the Zune to give that device a way to index files as they were added to the device. This is why the Zune was able to search very quickly for albums, artists, and songs. Apple solved that problem in another way, by requiring iTunes, and letting iTunes build the database when you installed new media. Although slightly different than the question you asked, hopefully this gives you some insight as to why Jelly Bean doesn't have UMS... or more specifically the Android device you are using.
As far as I know, you can still support UMS with Jelly Bean device, but there are very good reasons why your Nexus 7 does not.
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
Thanks for the very detailed explanation.
Now, when I connect the Nexus 7 to my Windows 7/64 Pro Machine, some folders are not visible.
One example is the Kindle Folder.
How does MTP determine which folder will be made available to the Windows Machine? Can I force it to "see/index" the Kindle folder, for example?

What's the location for the kindle folder? Im thinking theres an easier fix, I'll play around with it tonight.
Sent from my Nexus 7 using xda premium

CharliesTheMan said:
What's the location for the kindle folder? Im thinking theres an easier fix, I'll play around with it tonight.
Sent from my Nexus 7 using xda premium
Click to expand...
Click to collapse
The kindle folder is at
/storage/sdcard0/kindle

Chinpokomon said:
When you use UMS, the host machine is in charge of the filesystem. This means that Android would no longer be able to read and write to the partition while it was mounted. Because the sdcard partition in Android 4.x is a FuseFS partition; it is shared with data. This means that you won't run into the situation where you have "lots of space" but can't install applications -- the available space on your device is your available space for applications and any other data or media you want to store on your device. Because the sdcard partition cannot be mounted and unmounted, you can't use UMS.
MTP allows the device to keep the partition mounted and is an "application" on the device that knows how to show directory content, and to save or retrieve files over the USB. Given the design constraints, MTP gives the most flexibility and the best user experience with transfer rates being the most limiting factor.
Interestingly, MTP was also used for the Zune to give that device a way to index files as they were added to the device. This is why the Zune was able to search very quickly for albums, artists, and songs. Apple solved that problem in another way, by requiring iTunes, and letting iTunes build the database when you installed new media. Although slightly different than the question you asked, hopefully this gives you some insight as to why Jelly Bean doesn't have UMS... or more specifically the Android device you are using.
As far as I know, you can still support UMS with Jelly Bean device, but there are very good reasons why your Nexus 7 does not.
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
Is it possible then to create say a "Music" partition on the build in sdcard, which is mountable? Maybe make it a few GB's?

Related

Xoom storage, why MTP instead of USB file system, true APP2SD (from Google developer)

If you are still wondering:
- What is the breakdown of that 32GB Xoom internal memory (how many parition, how much space for apps / files)?
- Why Google is using MTP instead of USB file transfer on Honeycomb?
Here is straight answer from Google developer:
MTP is a big improvement over USB mass storage — for devices with lots of internal memory, a manufacturer no longer needs to come up with some hard partition between the USB mass storage and internal storage. Instead, they are all in one partition, with MTP providing access to the directory of media files that would normally be available through USB mass storage.This means there is no longer a need for apps on SD card for such devices, because what used to be the “internal SD card” is in the same partition as where applications are stored. The storage on your device can be used for either applications or media, depending on what you want to put on it. You aren’t stuck with how much space the manufacturer decided to leave for the two areas.
Oh also this means that the media storage doesn’t need to be unmounted from Android when it is being access through the PC.
Click to expand...
Click to collapse
http://phandroid.com/2011/02/27/mac-users-require-file-transfer-utility-for-android-3-0/
Finally, true APP2SD You now have 32GB to put all your apps!!!
Sounds like a good thing!
This is a great explanation. Thanks for posting.
There is no doubt that mtp has advantages over mass storage. On the other hand I miss the ability to attach it to any computer and access files. It is not a huge problem but does add a limitation that was not there before.
That saod it is nice being able to access files on my computer without losing access to the partition on the device.
Sent from my Xoom using XDA App
I only see a problem if you flash different roms and have to do full data wipes.
Sent from my PC36100 using XDA Premium App
jvs60 said:
I only see a problem if you flash different roms and have to do full data wipes.
Sent from my PC36100 using XDA Premium App
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Click to collapse
I'm sure future versions of CWM will be set to ignore that one folder.. I hope. Otherwise nandroid backups will take forever.
I'm not sure in terms of security it is a huge improvement; unless there is an option to turn it on/off somewhere.
Previously I would have to plug an Android device in to my computer, turn the device on, enter my unlock code, and then specifically allow the computer access via the USB. This morning I just plugged my xoom in and, poof, access to all my stuff.
At least before someone had to take my sdcard out at put it in their computer manually
Does MTP have anything to do with file size limit? I've seen posted on this forum that you can't load video files larger than 4gb onto the Xoom because of FAT32, is that still the case?
This MTP also seems to hide a lot of file from being seen by a pc. I open folders with File manager on the Xoom and see more folders namely the android folder which has game save data and other odd ball files. When hooked to a pc its blank. With MTP it seems all your allowed to do is transfer music, video and pics.
Malcus1 said:
Does MTP have anything to do with file size limit? I've seen posted on this forum that you can't load video files larger than 4gb onto the Xoom because of FAT32, is that still the case?
Click to expand...
Click to collapse
Still haven't got around to testing (so many things to try out!), but in some of the video threads, I've been told XOOM uses EXT4 format not FAT32, and thus, should not have that 4GB limit. I've been re-encoding video files to meet XOOM's current playback limitations, and have been reducing them to sub 4GB anyway, so I haven't tested that for myself.

Android File Transfer GS3

Was wondering about everyone's thoughts about this new feature. Personally I think it's crap. I can't view/read ANY files from the sd cards unless I FIRST transfer them to my mac...GAY! Why can't we just mount the SD cards like the GS2???
Can you please explain because I'm having this issue managing files from the sd
Sent from my SAMSUNG-SGH-I747 using XDA
20blks said:
Can you please explain because I'm having this issue managing files from the sd
Sent from my SAMSUNG-SGH-I747 using XDA
Click to expand...
Click to collapse
Basically, the mac tells me I have to transfer a file to the mac to view it....which sucks. With phones like the Galaxy S2, I was able to plug in and mount the sd cards and it would act like any other USB mass storage external memory drive.
I'm not quite understanding what you mean by "mac". This issue is KILLING me. I can't even find my sd card unless I use the built I file manager
Sent from my SAMSUNG-SGH-I747 using XDA
hapary said:
Basically, the mac tells me I have to transfer a file to the mac to view it....which sucks. With phones like the Galaxy S2, I was able to plug in and mount the sd cards and it would act like any other USB mass storage external memory drive.
Click to expand...
Click to collapse
It's due to the way that Ice Cream Sandwich handles the Memory. It's always live in the system. The only way to access the Memory is through MTP. There is an advantage of using such because it means that if your phone is formatted ext4 (speed increases if I am not mistaken) you can take advantage of that and still access the data. Both Windows and Linux support MTP, unfortunately Apple has not implemented such even though devices are starting to use MTP more these days.
For Further reading go here http://en.wikipedia.org/wiki/Media_Transfer_Protocol
From reading the site, there is a 3rd party implementation, not sure how up to date it is, but you might be able to make it work.
http://www.wentnet.com/projects/xnjb/ check that out to see if you can enable MTP on your mac which would reduce the need for Android File Transfer.
Also it has been a while since I have used Mac but you might be able to use these instructions to install a Ubuntu supported MTP software on your mac through X11 (allows you to run linux software on your mac) http://www.humans-enabled.com/2011/12/how-to-fix-samsung-galaxy-nexus-mtp.html
One final link.... http://forum.xda-developers.com/showthread.php?t=1355913
Thanks very much. I'm looking into it now
Ok.. I am using the Android File Transfer program and I can copy individual files to/from my GS3 BUT I cannot create folders for some reason. Even with the +Folder button. The error message reads: "Could not create folder. Try reconnecting or restarting your device." (Obviously I have done both multiple times.
Any thoughts?
on my PC it shows up as a portable media device and allows me to access both internal and SD memory
i did install the galaxy s3 drivers found on the rooting guides though
Can't transfer files with a Mac
M988 said:
on my PC it shows up as a portable media device and allows me to access both internal and SD memory
i did install the galaxy s3 drivers found on the rooting guides though
Click to expand...
Click to collapse
I can't get Android File Transfer to work with my Galaxy S3 running CM9 (or CM10, for that matter), either using MTP or using the camera setting. This is really annoying. Anyone know of a way to get it to work? I really wish that USB mounting still worked, so I wouldn't be required to use client software.
It works fine on my mac at work and I have a 5 year old macbook pro. It's not all that bad. I just use it to transfer files when I'm at work.
Sent from my SGH-T999 using xda app-developers app
hapary said:
I can't view/read ANY files from the sd cards unless I FIRST transfer them to my mac...GAY!
Click to expand...
Click to collapse
so it's perfectly acceptable and deserving of equal rights?
ergibson83 said:
It works fine on my mac at work and I have a 5 year old macbook pro. It's not all that bad. I just use it to transfer files when I'm at work.
Sent from my SGH-T999 using xda app-developers app
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Click to collapse
Well, it doesn't work for mine at all. Any tips? Did you have to anything to get it to work? Which ROM are you using?
Batmensch said:
Well, it doesn't work for mine at all. Any tips? Did you have to anything to get it to work? Which ROM are you using?
Click to expand...
Click to collapse
All I did was install the app and it popped up a window that displayed sdcard and phone. Each option displays a list of the content on that storage device.
Sent from my SGH-T999 using xda app-developers app

[Q] MassStorage

Is there a way to connect nexus7 using massstorage instead of MTP?
It is no longer called 'mass storage' it is called MTP. If you have the right drivers installed, usb debugging on, and working usb ports, MTP functions similarly to mass storage giving access to user accessible internal storage from the PC.
Groid said:
It is no longer called 'mass storage' it is called MTP. If you have the right drivers installed, usb debugging on, and working usb ports, MTP functions similarly to mass storage giving access to user accessible internal storage from the PC.
Click to expand...
Click to collapse
It is not semantics- MTP and MSC are two entirely different protocols with differing functionality. With MSC, the computer treats the device as external storage. With MTP, the device retains control of itself and only allows limited access to certain directories. For enthusiasts, MTP and PTP are far less practical than mass storage. For example, on my old dinc, I'd just drag and drop system files as needed. While it's not terribly inconvenient, the lack of mass storage capability has made the process a bit more involved and time-consuming.
Sent from my Nexus 7 using Tapatalk HD
The mass storage mode, at least on my phone, shared fat filesystems. It never exposed any of the partitions that are critical for a working android device. On the nexus7, there is not a partition that is formatted with fat. Instead, the /sdcard is on the same partition as /data, and only partially emulates how fat behaves. For mass storage to work, they would need to give the computer full control of the /data partition, which probably isn't going to work out well.
I maintain that mtp works similarly to mass storage. On my Droid Bionic with mass storage I can see and access the external sdcard (which the N7 doesn't have) and I can see the user accessible internal storage. This does not allow seeing /system or /data or operating system files, but does see internal storage for pictures, music, downloads, etc. When I connect my N7 I also have no access to /system or /data or operating system files, but have full drag/drop, read/write access to internal storage for user files including downloads, music, pictures, etc. It operates exactly as the Bionic in terms of read/write, and drag and drop access to user files.
Groid said:
I maintain that mtp works similarly to mass storage. On my Droid Bionic with mass storage I can see and access the external sdcard (which the N7 doesn't have) and I can see the user accessible internal storage. This does not allow seeing /system or /data or operating system files, but does see internal storage for pictures, music, downloads, etc. When I connect my N7 I also have no access to /system or /data or operating system files, but have full drag/drop, read/write access to internal storage for user files including downloads, music, pictures, etc. It operates exactly as the Bionic in terms of read/write, and drag and drop access to user files.
Click to expand...
Click to collapse
They are as similar as Windows and Linux. While they both have some overlap in functionality, they are two entirely different beasts that operate in different manners.
http://forum.xda-developers.com/showthread.php?p=27510082
Sent from my Nexus 7 using Tapatalk HD
Come on. I never said they are the same thing. I said they have similar functionality. I can read/write, drag/drop files both directions into the same memory areas on the N7 using MTP that I can to my Bionic using Mass Storage. The fact that they do it differently is a moot point. Please share your final thoughts as I have just shared mine. Bye.
Groid said:
Come on. I never said they are the same thing. I said they have similar functionality. I can read/write, drag/drop files both directions into the same memory areas on the N7 using MTP that I can to my Bionic using Mass Storage. The fact that they do it differently is a moot point. Please share your final thoughts as I have just shared mine. Bye.
Click to expand...
Click to collapse
Actually, you implicitly stated that they are the same thing, just by with a new name. The simple, qualifiable fact remains, however, that MSC allows greater access to internal file structure than MTP. Conversely, MTP allows for transfer of some things that are simply not possible with MSC such as some metadata and DRM. This isn't a matter of opinion, as it is 100% empirical.
Sent from my Nexus 7 using Tapatalk HD
Actually it's pain to get mtp to work on Linux and its alot easier to use MSC. they work entirely different
Sent from my Nexus 7 using Tapatalk 2
So how do i backup my saved games etc.? These filew are not visible on mtp. I can use tib, sure, but I would like just saves, not whole game.
I can use some weird file manager on device and upload It to PC using samba, but it is VERY inconvenient.
Also I hope to be able to fix mediaserver issue when I would be able to see all files on the PC.
AW: [Q] MassStorage
evlo said:
So how do i backup my saved games etc.? These file are not visible on mtp. I can use tub, sure, but I would like just saves, not whole game.
Click to expand...
Click to collapse
You can use adb backup ... but there might be an issue with backing up the shared filesystem (at least in 4.0.x) the backup couldn't be restored without repacking the backup file.
Sent from my Nexus 7 using xda app-developers app

Someone please write a mass storage app for lg g2

Mass Storage availability would really make this phone complete for me. Is it that difficult? I have tried a bunch of other apps with no luck . I know Samsung wrote an App for their phones.
Danester said:
Mass Storage availability would really make this phone complete for me. Is it that difficult? I have tried a bunch of other apps with no luck . I know Samsung wrote an App for their phones.
Click to expand...
Click to collapse
No they did not. Some phones with external SD cards you can still access as UMS. No modern phone can you access the internal SD that way as the internal "sdcard" is just a subfolder of the /data partition. UMS requires the device to unmount from the phone to mount on the PC, and it just simply isn't going to work.
There are dozens of apps in the market to transfer files over wifi in various forms.. scp, smb, ftp, browser, etc..
Personally I use a scp server that will run as root so it can use port 22 and use rsync when I want to move large amounts of files around.
Danester said:
Mass Storage availability would really make this phone complete for me. Is it that difficult? I have tried a bunch of other apps with no luck . I know Samsung wrote an App for their phones.
Click to expand...
Click to collapse
Why do you want to use mass storage so much? if it is to transfer files to a mac, download AFT here...http://www.android.com/filetransfer/
I My old htc and earlier phones with android had mass storage. The reason i want it so bad is that my car has ford sync and with ums through usb, i can verbally select tracks i want played without looking at the phone. Bluetooth works but i have to look down at the phone to change songs. Also with old versions of android i could get the stereo sync system to read back my texts and i could verbally send texts also. It was awesome. Iphones work perfectly but i hate iphone. Android worked until icecream sandwich. Its a huge loss for people with stereo systems that have verbal command control across all makes of cars.
Sent from my LG-D803 using xda app-developers app
With HTC One X I could mount it from the recovery. But I guess G2 would not have that option. (One X doesn't have SD, it's internal memory like G2)
+1
khaytsus said:
No they did not. Some phones with external SD cards you can still access as UMS. No modern phone can you access the internal SD that way as the internal "sdcard" is just a subfolder of the /data partition. UMS requires the device to unmount from the phone to mount on the PC, and it just simply isn't going to work.
There are dozens of apps in the market to transfer files over wifi in various forms.. scp, smb, ftp, browser, etc..
Personally I use a scp server that will run as root so it can use port 22 and use rsync when I want to move large amounts of files around.
Click to expand...
Click to collapse
There are phones that do not support mass storage, such Xperia S or U, but there were apps written by XDA members that allowed me to use mass storage. Why there is no such app for G2?
+1 +1 +1

USB Mass Storage Mode?

OK, what Kit Kat ROMs have USB mass storage mode?
If a ROM does have it, exactly how/where is it enabled?
Either a ROM doesn't have it or if it does the dev hides it some place and requires digging through 100's of stupid pointless posts to maybe if you are lucky, find the answer.
I'm at the point with this USB mass storage B.S. that I'm ready to leave Android completely and get a flip phone. Whomever thought it was a good idea to remove it was an idiot and whomever signed off on it was even a bigger idiot.
Lokifish Marz said:
OK, what Kit Kat ROMs have USB mass storage mode?
If a ROM does have it, exactly how/where is it enabled?
Either a ROM doesn't have it or if it does the dev hides it some place and requires digging through 100's of stupid pointless posts to maybe if you are lucky, find the answer.
I'm at the point with this USB mass storage B.S. that I'm ready to leave Android completely and get a flip phone. Whomever thought it was a good idea to remove it was an idiot and whomever signed off on it was even a bigger idiot.
Click to expand...
Click to collapse
MTP is absolutely terrible, completely half baked and totally unreliable.
Right now I just discovered that ChromeOS doesn't even support MTP... Google's OWN PRODUCT...
I'd like to know the answer as well.
I understand the frustrations but the problem with mass storage is that it surrenders all control of the internal storage to a PC not a problem when that's a different chip but on the n7 and most new smartphones its an emulated partition and giving over total control would mean that android cannot function at the same time. This was brought in to stop manufacturers using two separate chips giving you loads of "storage space" but very little application space. Its a work in progress and has many issues but its here to stay I don't think any ROMs will support USBMS as it not possible on a single chip without shutting down android.
Sent from my C5303 using xda app-developers app
LOL. In camera mode you have access to the "Pictures" folder and is readable by Windows and other OSes. All that needs to be done is duplicate the same process and direct it to a folder called "Storage" with full permissions for the folders contents. This essentially simulates USBMS. You can even redirect mounts to that folder so that apps see it as a storage area as well so things like map data and so on are put in the "Storage" folder.
I don't have the time to mess with this but it can be done and something almost exactly like this has been done before on almost every OS.
Lokifish Marz said:
LOL. In camera mode you have access to the "Pictures" folder and is readable by Windows and other OSes. All that needs to be done is duplicate the same process and direct it to a folder called "Storage" with full permissions for the folders contents. This essentially simulates USBMS. You can even redirect mounts to that folder so that apps see it as a storage area as well so things like map data and so on are put in the "Storage" folder.
I don't have the time to mess with this but it can be done and something almost exactly like this has been done before on almost every OS.
Click to expand...
Click to collapse
I imagine it can be done but it wouldn't be mass storage and would require apps to be compatible it may have been done on other systems but how much space should this storage folder be allocated because it would no longer be avalible to install apps. In camera mode android still retains control of the folder other os can read that folder but files must be copied off the device to be edited. It would be good if android could mount the SD card as mass storage.
Sent from my C5303 using xda app-developers app
No it would not technically be mass storage, thus the "simulated" comment. As far as other OSes, it's already been done to a point on android already via the simulated partition that's already in use. This has also bee done using third party apps to mount folders as virtual drives.
App compatibility, if the folder is used as mount point then it is transparent to the OS and the apps. This has been done for some time now using third party apps.
The folder size could have the same limitations that the storage area has already been limited to. If coded so that it is part of the boot process then everything outside of system apps would only see the virtual area. Kind of like what's being done right now.
Dual mount. This has been used with much success and allows for PC and Android access to the same storage area at the same time.

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