Synchronizing folders

I've been battling with this for years, unsuccessfully.

Whereas there are many PC programs that can synchronize two folders (with all the files and subfolders inside them), Phones and Tablets appear to mostly offer cloud synchronization, and so when you ask to sync two folders on the same device, 100% of the time the answer involves the word 'cloud'... and syncing with desktops... even after I say I am not asking for that and I try to be specific about only wanting to sync two folders on the same device.

I am not able to get this question answered on other Android forums or in the Smartphones & Tablets forum section here.
People don't know what syncing two folders means or why it's important. They automatically immediately go to 'cloud syncing' but that's not what I am asking.

What exactly are you asking? Your title suggests two folders under linux, though I am not sure why you are referencing the Android forums...

If its linux you have several options. Unison is the first thing that comes to mind.

rsync with a cron is the second.

Can you more clearly define what you are trying to achieve?

You can also try SyncThing if you mean how do you sync two folders, one on a mobile device and one on a desktop.

Hi stratus. I came here as a last resort on the off chance you guys might know.

I simply need to insert an SD Card into a phone/tablet and sync a folder on it with a folder that's on the Android phone/tablet already. I cannot find an app that can do that and am asking if someone knows of one - I tried many from the Google store and the furthest I got was an app syncing only the top level files but not syncing sub folders.

I am not sure if this is relevant, but I manage files & folders on my Moto G with the app "Airdroid".

Article

I particularly like the ease of use with Airdroid, but pls disregard if not useful.

There are a lots of ways to sync non-local folders but I dont know any to sync local aside from installing rsync on your device and typing/scripting it

It is August 2015 and $800+ Tablets & "Smart devices" are becoming PC replacements.

If the task was to sync two folders on them and there was no internet connection, there is no software in the world that can accomplish that task with a click of a button?
Whoever would write such a program today would be the first and only person in the world to do it? I don't know what to say... except of all the millions of people using sync software on PC, most own Android devices... surely their needs would transfer to Android.... how can they not? And whoever made such a program would corner the market immediately, because it would be the only program in the world?


How would they not become millionaires if they charged just five bucks for it? Surely I am not the only person using sync programs on a PC religiously who would gladly pay five bucks to be able to do the same on all my non PC devices?



This bizarro world stuff reminds me of our conversation from half a decade ago when I installed Linux on a flash drive and Linux immediately !!!FUBARed!!! my Windows drive master boot records!!!

A look back at that:

funnyperson1 said:

Here is what actually happened, there are two parts to the bootloader. The first part is the GRUB loader that gets written to the MBR. The second part consists of the binary modules, configuration, etc. needed to boot your operating systems. The second portion usually is stored in the /boot folder of the partition you install to. Now the GRUB loader is told where to look for this GRUB folder, and if it can't find it (USB drive is removed), you won't be able to boot. These two components can and often are written to different drives.

The real issue is what I consider a user-interface bug in the Ubuntu installer. Instead of explicitly prompting the user regarding where the boot loader should be installed, it usually assumes /dev/sda (first bios drive) and gives you the option on a drop-down menu that is easy to skip through. So you do have the ability to tell Ubuntu where to put the boot loader, it's just easy to miss it. Also there was a bug with previous versions where even if you told it where to install the bootloader, it would still install on /dev/sda. Perhaps this is what you encountered.

Click to expand...

The non PC world boggled my mind back then and it still does...

I guess I dont see a use case where I would want to sync two folders on the same android device. I use a plethora of methods to sync folders between my android device and something else.

SpiderOak, Owncloud, syncthing, btsync. SpiderOak is a "cloud service" but it in this capacity the only thing the server does is facilitate the connection. I have never tried to use the sync function without a working internet connection.

Owncloud can run with or without an internet connection. All things listed require a network connection.

I guess the only reason I can think of to do what you are asking (which is NOT a ludicrous ask btw) is you need to transfer some file via micro usb when no network of any kind is available. Although, I dont know how such a case can exist, what with being able to create mobile hotspots if you arent within range of some network or other

So we agree that if you have 10GB folder in the palm of your hand on an SD card, (which can be popped into Windows and synced in seconds) - the same cannot be done on a non-windows system.

Let me tell you what the background story is and what this is about. Let me first try to get some screen shots... And post later.

So let me tell you what this is all about now. Let's connect two phones to a PC.
An old original Samsung Galaxy and a newer modern Samsung Galaxy S5.

Let's see what happens on non-modded, non-custom, original phones:
Original Galaxy shows up as a drive letter, for example G:



whereas modern phones no longer show up as drive letters, the Galaxy S5 cannot be connected in UMS Mass Storage Mode. No way no how unless you install a modded operating system, modern devices ONLY CONNECT with MTP (Media Transfer Protocol) or PTP (Picture Transfer Protocol) which looks like this:




Now,
only if the card is mounted as a drive letter, only then is it possible to quickly synchronize a folder containing a large number of files.

You cannot quickly synchronize if you have the above pictured connection on your PC, a 'Portable Devices' connection, which as you can see is what Galaxy S5 connected to PC looks like, as pictured above, in other words it can only connect as a MTP/PTP connection. THERE IS NO APP THAT CAN CHANGE THAT. Those that claim they can, cannot do so on new phones.

Cloud syncing EXISTING 10 GB folders takes unacceptably long. FTP syncing takes FOREVER in comparison to SECONDS it would take if you can connect a device and get it to show up as a drive letter. So in my example above. Identical sync of a 10GB folder with thousands of files takes SECONDS on the Galaxy S1 because it is mounted as a drive letter and a thousand times longer to do an identical sync on modern devices like Galaxy S5 which cannot be synchronized quickly because they do not show up as drive letters.


So then, to get around this problem, I could pop the SD card into a PC, it OF COURSE shows up as a drive letter and thus can be synced QUICKLY.
All I have to do now is place that SD card in all my other devices and the stupidity of no UMS Mass Storage Mode on modern devices would be solved by syncing right off of the external sd card!


And I thought I could do all that but guess what.... non-Windows devices CANNOT sync two folders directly. No one in the entire world thinks anyone anywhere would ever wish to sync two folders directly when they step away from Windows! This is crazy.



This is where we were 10 years ago and nothing has changed! :

c627627, I removed the image in the spoiler because of the language it had. Please be sure to review images before posting them.

I've never had a problem navigating to my Note 4's camera directory and copy/paste files from the device to my PC. Sure it doesn't show up as a mass storage device, but MTP/PTP have never presented issues with me moving my files from the device. Now, if you're looking to do it in an automated fashion, maybe that's where you're running into problems?

In every thread on every forum I have asked this, the majority of posters interpret my question as either copy/pasting or cloud syncing, and frequently as if I am asking about settings backups.
Transferring files works fine.

This is about synchronizing two folders. I just had a discussion last night - people think syncing is a word that ONLY means cloud back ups.

Meanwhile syncing two folders is what people have been doing on PCs long before they invented cloud storage or smart phones.

I then asked what term would you use?

They answered SYNCING FOLDERS, which is the word I used with them originally. So I don't know why people do not understand what synchronizing two folders means.

It is not copy/pasting. You don't copy/paste a 10GB folder after making only a few changes. You sync the two folders.

You simply make the target folder delete or add ONLY the files it is missing from the original folder.
If the folder is on an SD card - then you can simply insert that SD card and sync the target folder.


Unless you are not using Windows. It appears "no one" does that outside of Windows? It's still hard to accept.

Well under linux sync works just fine. As I said earlier, using Unison under gnome 3 and Antergos/Arch with a Nexus 5:

c627627 said:

It is not copy/pasting. You don't copy/paste a 10GB folder after making only a few changes. You sync the two folders.

Click to expand...

To be fair, syncing is just copy/pasting without over-writes. A simple 'no to all' tickbox when prompted to overwrite will yield the same results. Probably wastes a few CPU cycles to do it that way versus an application designed to sync, but outside of the manual step of clicking a button, it's no different (hence my assumption that you're wanting to do it in an automated fashion).

[edit] I guess a benefit of a true sync is to remove files that are no longer in the source directory. I very, very rarely delete anything so this concept is foreign to me, but I could see that it has its place.

tbh, I'd just script something to do it... but I'm sure something Stratus recommended will work as intended.

pcgamer4life, that would not work, it is not copy/pasting at all.
If I add a few files and delete a few files out of fifty thousand files.... then making another near identical folder to also add those few files and also delete the same few files can only be done in a few seconds if there is a sync program and then ONLY if the target folder is either local or if the drive the target folder is on can be displayed on a PC as an actual drive letter.

NEITHER is possible on the latest tablets and smart phones.


Stratus_ss, I'm sorry for joking earlier.
I came to the Linux forum because I know you hang out here and to see if you or the other Linux guys know of an Android app that can sync two local folders. I renamed the thread which used to have the word Linux in it just to prevent the forum moderators from nuking my thread before someone like you could read it. My question is about doing this on Tablets and Smart Phones.

Forcing Samsung Galaxy 5 into a UMS Storage Mode would also help. I was very close to get a guy who made a program which forces Galaxy 4 away from MTP and into the UMS Mass Storage Mode to also make Galaxy S5 do that, but he had no time and could not be bribed.

I assume if you root your phone you can do whatever you want with it and do that without any issues?

After rooting it, you have to also get rid of the entire operating system and replace it with a modded one like CynogenMod for example.
But installing a custom OS is not always an option, so rooted devices still have the original OS, and are thus forced to stay in modes which do not allow their drives to be mounted and displayed as drive letters.

So then the only option is to sync a removable SD card in Windows then take the card and use it as a sync source.

I have actually found a program that can direct sync but it does not sync subfolders, only top level files.

Obviously the point now is IF anyone ever in the future comes across ANY app that can direct sync -- *no cloud* -- please bump this thread.

I believe I posted that in the other thread, that Google added security precautions to not allow an app full access to a file system without giving extra permissions I believe (or after being rooted) I think with either kitkat or lollipop.

Janus67 said:

I assume if you root your phone you can do whatever you want with it and do that without any issues?

Click to expand...

Kinda... It'll give you admin access to everything on the device but adding in a USB mode is something else.



However rooting would let one run scripts

The thing to remember here is that this can be done using FTP.
This can be done using MTP/PTP connection, I have PC programs that can sync Android phones connected to Windows through MTP/PTP.
This can be done using the cloud.

So any solution is not a solution if it simply synchronizes - I can find a way to ultimately do that.


What we are looking for here is a QUICK SYNC, none of the above mentioned methods are suitable for super-fast computing when there are no limitations that MTP/PTP connections impose.


UMS Mass Storage Mode or SD card sync are the only two methods that are superfast.