Warning email and site response to be very slow
I've got several warning email as the following :
At [xx/Aug/2010:xx:xx:xx -xxxx], web server with pid=xxxxx received unexpected signal=4, a core file is created. A new instance of web server will be started automatically!
Get it per every several hours. And seems to be more frequent. The last 2 warning emails are within half an hour. And just before to receive each warning email, the litespeed would before very busy and no response.
I'm very new to litespeed. Any suggestion/hint of how to check the reason? Deeply thx.