While it is Ubuntu, that isn’t the issue at all, and this isn’t the first time I’m using DataLoader…
Oh the following shows this isn’t the issue(unless DataLoader opens over 800000 files, in which case i would like to know why  ):
yoni@yoni-Lenovo-Z710:~$ lsof | wc -l
89114
yoni@yoni-Lenovo-Z710:~$ cat /proc/sys/fs/file-max
791958