Linux fork () : resource temporary unavavailable - linux

Question

How to debug following points just to find out exact reason which resource exceeding limit
How many process currently running
How many process running for per
user No. of opened files for per process.
Total no. of opened files for all process.
No. of process limit No. of open file limit

Answer 1

There can be multiple ways to go about what you are trying to achieve, e.g. you could get all the information you need by evaluating /proc/ fs. Below is a list of utilities you could use to debug the actual resource issue.
Good luck.
How many process currently running
ps -eaf | wc -l
How many process running for per user
ps -fu [username] | wc -l
No. of opened files for per process.
lsof -p < pid > | wc -l
Total no. of opened files for all process.
You could iterate over all the pid as shown above and make use of lsof command. Here, you might have to execute the command as root, else you would get permission denied while doing lsof
No. of process limit No. of open file limit
For a specific terminal, you could do
$ ulimit -a
core file size (blocks, -c) unlimited
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 15973
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 15973
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited