crash server due to high load

hello; sometimes on these days about 3-4 times per day, my server go down, what kind of log files required to invistigate main issuse and solve it? for example: part of email: Service chkservd Memory Information Used 2.66 GB Available 1.08 GB Installed 3.74 GB Load Information 204.04 207.43 212.60 as you see on above; this is huge overload,its normal to be 1-3 !!! -i have only 5 websites on this server -- another email: Process ID 25454 Process UID 498 Process Username mysql Process Total Virtual Memory 4973516kB Process Anonymous Resident Set Size 89616kB Process File Resident Set Size 372kB Process OOM Score 66 Status Out of Memory ? Memory Information Used 3.13 GB Available 627 MB Installed 3.74 GB Load Information 257.03 250.04 223.00 IOStat Information avg-cpu: %user %nice %system %iowait %steal %idle 11.86 0.18 1.36 16.37 0.00 70.23 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 135.78 5073.95 4333.14 414404412 353900664 sdb 1.04 181.81 180.64 14849122 14753248 Preview of "cpanel_tailwatchd_log_tail.txt" [3884] [2016-01-24 20:30:00 +0330] [Cpanel::TailWatch::Eximstats] Resetting email limits to new starttime of 1453654800 [3884] [2016-01-24 19:30:00 +0330] [Cpanel::TailWatch::Eximstats] Resetting email limits to new starttime of 1453651200 [3884] [2016-01-24 18:30:00 +0330] [Cpanel::TailWatch::Eximstats] Resetting email limits to new starttime of 1453647600 [3884] [2016-01-24 17:30:00 +0330] [Cpanel::TailWatch::Eximstats] Resetting email limits to new starttime of 1453644000 [3884] [2016-01-24 17:20:48 +0330] [Cpanel::TailWatch] [INFO] Flushing all readers [3884] [2016-01-24 17:20:48 +0330] [Cpanel::TailWatch] [INFO] tailwatch saving positions and reloading configuration on SIG [3884] [2016-01-24 17:17:47 +0330] [Cpanel::TailWatch::Eximstats] [SQLERR] Could not execute query, logging SQL to /var/cpanel/sql [3884] [2016-01-24 17:17:47 +0330] [Cpanel::TailWatch::Eximstats] [ERR] SQL Failed with error (Incorrect datetime value: '0000-00-00 00:00:00' for column 'countedtime' at row 1): INSERT INTO smtp (mailtime,msgid,email,processed,transport_method,transport_is_remote,host,ip,deliveredto,router,deliveryuser,deliverydomain,unique_id) VALUES(FROM_UNIXTIME('1453643266'),'1aNL18-00038r-0F','c***@a****.in','2','virtual_userdelivery','0','localhost','127.0.0.1','c***@a****.in','virtual_user','b*****','a****.in','192') DBD::mysql::st execute failed: Incorrect datetime value: '0000-00-00 00:00:00' for column 'countedtime' at row 1 at /usr/local/cpanel/Cpanel/TailWatch/Eximstats.pm line 1075, line 1234. [3884] [2016-01-24 17:17:47 +0330] [Cpanel::TailWatch::Eximstats] [SQLERR] Could not execute query, logging SQL to /var/cpanel/sql