ffmpeg error, won't combine parts

[Minkafighter]

trying to download a vod, when finished downloading it tries to combine the parts but it throws an ffmpeg error as shown below.
./concat_ubuntu -vod=111836368 -start="0 0 0"

......................................................
Combining parts

ffmpeg error
Deleting chunks
Deleting temp dir
All done!
root@vps:~/twitch#

This only happens on "long" vods. It doesnt happen on https://www.twitch.tv/videos/112067373 .

[ArneVogel]

This might be caused by ubuntus limit on open files. Long vods can have over 4096 chunks that have to be combined by ffmpeg. My guess is that ffmpeg opens all the chunks during the combining process and this caused an error from ubuntu. I had similar problems with the file limit on ubuntu before.

Can you increase the open file limit and try again?

[Minkafighter]

This sadly didnt work:

........................
Combining parts

ffmpeg error
Deleting chunks
Deleting temp dir
All done!
root@vps: ulimit -n
512000
root@vps:

Is there a way to tell the program to download bigger chunks? Or tell ffmpeg to only combine 2000 or 4000 chunks at once?

[Minkafighter]

I found something... on openVZ i guess you cant change the open file limit, as you dont have access to enter this command:

root@vps:~# sudo sysctl -w fs.file-max=1024000
sysctl: permission denied on key 'fs.file-max'

Entering this command in a KVM server, will result in no "permission denied" and i can combine all parts! Yay, i guess! :D