Btsync Crashing On Synology Rs814 Dsm5. How To Debug?


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I'm having issues with the latest BTSync 1.3+ BTSync builds on my Synology RS814 running DSM 5. It crashes randomly with no apparant reason and I have no clue how to debug or investigate it.

It can run fine for 2-3 days or crash every hour, so it's totally at random.


Any input is greatly appreciated! Thank you.

Kind regards.

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I've a DS214se with DSM 5.0-4482 and installed the BitTorrent Sync 1.3.93 package via

To enable debug log, I've to


1. telnet to the syno using root login (same password like admin)

2. go to /volume1/@appstore/btsync/var (here reside the sync.conf and sync.log)

3. create the file debug.txt with just the content of 4 chars FFFF

4. restart the package


debug output will be written to the sync.log file afterwards.

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I meanwhile run 1.3.94 on my Synology DS214se.

Your RS814 and my DS214se are using ARMv7 processors, so it is no problem to


1. stop the BitTorrent Sync package on the Synology and

2. replace the btsync binary in directory /volume1/@appstore/btsync/bin with the ARM binary you can download at ; give it with chmod and chown the rights 775, owner btsync and group root


Regarding the failing debug ... I can' say whether you're doing something wrong. If you created the file debug.txt with FFFF as content as mentioned in the correct directory and you restarted the package, you should immediately see in the sync.log tons of new entries like the peer pings i.e.

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Sadly, it crashed again....


Here's the sync.log file:
And here's the sync.log.old file:


I can't find anything special/odd in there...


What could this be causing? I'm having these issues since BTSync 1.3+. BTSync 1.2+ ran perfectly.

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I have analyzed your logs.

Check please /volume1 permissions.  I think btsync on your NAS has insufficient permissions to this folder. 


Commands for checking: 

# ls -lsa /volume1

# ps -o user,cmd | grep btsync


Try to:

# chmod -R a+rw /volume1 

for first.

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Perhaps I may jump in with my experience using the little DS214se:


1. try "ps -w|grep bts" to get what denis4inet is interested in

2. if you installed the btsync package from synocommunity then they use the internal user "btsync" ... unfortunately this user is NOT visible by DSM webGUI.

3. If you created shared folders within the webGUI to place the btsync directories into you need to allow the group "users" having access to it otherwise the user btsync has not sufficient permissions to touch these areas. In the DSM webGUI do for all shared folders you use with btsync:


In the webGUI goto Control Panel -> Shared Folders -> Edit the specific shared folder -> Permissions -> Switch to Local groups -> activate READ/WRITE for the group "users".


That was the only trick on my system to get it to run without any problems.

If you created subdirectories within the shared folders using a user not being a member of the group users, it could be that you have to manually correct things in a telnet session.

For this check any subdirectory and file in a folder used by btsync and see whether group users has access. The command the change the group permission is "chgrp" and can be used recursively with the "-R" parameter of course.

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Thanks for your reply @JimKnopf,


Here's the output of "ps -w|grep bts"


RS814> ps -w|grep bts15233 btsync    177m S    /usr/local/btsync/bin/btsync --config /usr/local/btsync/var/sync.conf20069 root      4036 S    grep btsRS814>


Yes, I installed the btsync package from the synocommunity.

Should denis4inet's fix not work, I will apply your steps. So far it's still running.


However, I do have a question about this behaviour:


It's been like this for over 2-3 weeks now. What could this be causing? MicroServer is synced using a read-only key.

Thanks in advance!

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  • 2 weeks later...

It has been running like a champ since I've applied those commands @denis4inet

Apparantly it was an rights issue indeed. Thank you very much!

Still, I am curious why some folders never finish syncing, as shown in the screenshot in my previous post


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