How to troubleshoot "permission denied" problems ?

[tuxolero]

Hi,
I have transferred all my torrents to my Banana Pi in order to no longer need to run my PC 24/7. Both the PC and the Pi are running Arch Linux with XFCE. And I'm using transmission-gtk on both of them.

This is what I did (on the PC):

• rsync -vcaHAX /torrents/ banana:/torrents/
• rsync -vcaHAX ~/.config/transmission/ banana:~/.config/transmission/

Both target directories already existed and were empty.

After that, I could start transmission-gtk on the Pi, and all torrents were there. I also could "verify local data" successfully for all torrents. Seeding also works. So far, so good.
But as soon one of the files continues downloading (seeder comes online), I get a "permission denied" error. It happened on all torrents where seeders came online so far.
Unfortunately, the file path is truncated in both error messages (in the torrents list as well as in the "properties" dialog), so I can not even check which file is the one having the problem. And I did not find any logs.

This is what I have already checked on the Pi:

• /torrents is mounted read/write (external Sata HDD), no file system error, I can manually create files and also append to them.
• all directories and files are owned by user "tuxlero"
• transmission-gtk is running under user "tuxlero"
• all directories have permission 770 (rwxrwx---)
• all files have permission 660 (rw-rw----)

And now I'm clueless what I can check next.

Any ideas ?
Thanks and Regards,
tuxlero

[tuxolero]

Update:
Well, it seems that the problem is not related to the transfer of the files from one computer to another. I have to correct one of the things I wrote in the above message:
Not all torrents are affected.

And after clicking "start now" on the errorneous torrents multiple times, they started working in the end. After that, the Banana Pi was running 24/7 for several weeks without problems.

But Today, I noticed something new: I needed to reboot, and after this, the problem was back. Some of the torrents went "Error: Permission denied" and needed some intensive care. Let's see how many are affected and how many times I need to click "start now" on them.

I think a more detailed error message (maybe in a log), containing the complete (i.e. not truncated) filename and the exact operation on the file that was tried, would help.