Today I found that Apache on my server was very slow and a lot of child pid xxxx exit signal File size limit exceeded (25) errors in error_log.

It turned out that one of my applications log files are 2GB. WHen apache process read a file over than 2B it will give that error. It could be apache logs or applications log

How to fix it?
Let start by searching your apache logs

find /var/log/apache2 -type f -size +20000k -exec ls -lh {} \; | awk ‘{ print $9 “: ” $5 }’

If you still can not find the large files – search the whole system

find / -type f -size +20000k -exec ls -lh {} \; | awk ‘{ print $9 “: ” $5 }’

(in this example i only search for files larger than 20000k (20MB) – you can change the number to meet your needs.

After finding the large files, delete them or rename it.