If VDS freezes, where can I find the logs to find out the reason?

Question

linux

Hi all . Increasingly began to fall VDS. Characteristics
Processor: Xeon E5620
RAM: 2 GB
HDD: 50 GB
There are two sites with 1000 traffic each. Sites on DLE
The server runs on CeotOS using Nginx Apache
The strangest thing is that the server works quietly when both sites have online users of 20-30 people on the 1st and 20 on the second.
And it usually freezes when there are 5-7 people on the site and 1-2 on the second. Vesta is installed, the total load of the system when there are 20-30 people on the
site 0.00-0.10 (Shows in the Vesta -> Server section)
it is the logs that need to be looked at. There are a lot of them in the LOG folder (Someone advised me to look in syslog, but I don’t even have it.)

Answer 1

This answer will soon become my standard. Get an admin.
In your case, you can contact the hoster's TP, suddenly they will help? Maybe even for some money...

Answer 2

Check limits ulimit -n. I often see low values ​​on servers with VestaCP.

Answer 3

/var/log/syslog will tell the whole truth.

Answer 4

Don't set any limits. It all depends on the correct configuration of web servers and, of course, codes. And another reason may be a SYN attack, get php posts, especially if you have apache2 installed.
In general, there can be many reasons. Check the apache or nginx logs, check the connection logs with the netstat command, or with the top command.
Otherwise, if you want I can help.