After having some trouble with "too many files opened" error, I made some research and I found out that Linux has by default some limits concerning maximum number of files that a user can open. Fortunately, we can change that.
First let's see how many files can we open. So, in a terminal type
ulimit -n
It will return the number of files. Default is 1024.
To change that limit, do the following:
1) Open Dolphin as root
2) Go to /etc/security/ and open file limits.conf
3) At the end of the file add the following:
* soft nofile 4096
* hard nofile 10240
* hard nofile 10240
4) Save and restart.
5) Open a terminal and type ulimit -n again. It should return 4096.
Observations:
- This will increase the number of files for all users. If you want to modify those values for only one user, it is possible, but I didn't try. Basically, you should replace the * character at the beginning of the line with the username (?)
- Do not omit the * character at the beginning of the line. it means "all users". A line must have 4 parameters, * being the first.
- The values I used are those recommended on different forums. I can't offer an explanation for them.
