android inotify and no root: the 8192 folders limit

[cregox (c+aue)]

continuing from

"failed to set up inotify handler. please increase inotify limits"

@imsodin Ah, that’s why I didn’t experience this on my phone as I’m using root to sync huge amounts of data without problem. Thanks for helping to investigate this issue. Should I make a PR to add an explanatory string under the label “Watch for changes” stating “This option should not be enabled on folders containing more than 8.000 objects” if the app detects it is not running under the root account?

why does “watching folders” matter?

• could it be just about “real time” sync?

if so, i could go with a better warning message that would say simply:

android needs root of you want to live update more than 8192 folders. {link to faq} [dismiss warning]

that “close” button (dismiss warning in my instance) is missing right now, which makes me believe this is a more important warning…

• is it that syncthing needs this to know about changes and so folders unwatched by this can never reliably sync for some reason?

if so then the comment there about adding a proper warning would be more than sufficient for me!

android with no root can only keep 8192 folders in sync, and that’s counting ignored ones when excluded!! please, consider using less folders. {link to faq}

… or something. i didn’t really get that last point about ignored folders entering this “quota”.

[imsodin (Simon)]

As already written in the other topic: The error has nothing to do with being root or not and it is not specific to android. Neither is the 8192 number of much significance, that just seems to be the default on many systems.

@cregox

that “close” button (dismiss warning in my instance) is missing right now, which makes me believe this is a more important warning…

The only way to dismiss this warning is to either increase the inotify limit or disable watching for changes.

I suggest you read this to understand how scanning and watching for changes works/what it does: Understanding Synchronization — Syncthing documentation

[cregox (c+aue)]

thanks for the engaging!

and for the link.

isn’t this category specific to android app, though?

and now that it’s a bit clearer for me, how about this warning then?

android reached the limit of %inotify folders to be watched. it’s possible to increase the limit with root. for more information: (link)

all 3 suggestions are basically the same: they explain what’s happening and what can be done, without needing to dig more than a simple and concise flow of text (through a few links, in last case).

i really do think both the message and the link are begging for better explanations!

on android, the only way to increase the limit is through root, as far as we all know, right? having that information on at least on the link could be very helpful! plus the link you just gave us, about “what watching even means”.

sorry for all my ignorance!

[tomasz86]

@cregox

on android, the only way to increase the limit is through root, as far as we all know, right?

Not necessarily. If the device has unlocked bootloader and/or access to custom recovery, then you can modify the files there, without actually rooting the OS itself.

However, otherwise yes, you would need root access to do the modifications.