I am having a php mail() which causes crash to the whole server, for a moment unable to access virtualmin, shell access, public_html pages, the whole server goes down, after some time all works fine. How to figure out what is causing such huge problem to crash the server
Best way to find out what's going on is by checking your server logs. They are in following directory.
/var/log
there are lots of logs, which log to check for the server crash, below two lines are from syslog, are they causing the crash or have to check all the logs
Nov 26 23:28:25 www named[1459]: network unreachable resolving 'no-reverse-dns-configured.com/DS/IN': 2001:503:d414::30#53
Nov 26 23:28:25 www named[1459]: network unreachable resolving 'no-reverse-dns-configured.com/DS/IN': 2001:502:1ca1::30#53
Go through syslog and look for errors. Low memory is a common cause for crashes. Look for memory related lines. Also look at the Virtualmin logs directory for clues.
syslog, found but clamscan is disabled from server>bootup & shutdown section webmin
Nov 27 12:20:54 www kernel: [1241277.478711] Out of memory: Kill process 32211 (clamscan) score 355 or sacrifice child
Nov 27 12:20:54 www kernel: [1241277.484350] Killed process 32211 (clamscan) total-vm:605896kB, anon-rss:454048kB, file-rss:1548kB
clamscan us used by maldet for real-time protection. How much RAM does your server has?
1Gb Ram 260 mb swap memory
171 process running 1 Gb Ram 260mb swap memory,
processor Intel(R) Xeon(R) CPU E5-2676 v3 @ 2.40GHz, 1 cores
| CPU load averages | 0.49 (1 min) 0.40 (5 mins) 0.94 (15 mins) |
Killed
Virus scanner failed to response within 30 seconds
From MAILER-DAEMON Tue Nov 27 15:33:07 2018
Subject: Undelivered Mail Returned to Sender
procmail.log file, how to solve this error