有一台虛擬機器系統是
Red Hat Enterprise Linux Server release 6.5
2.6.32-431.el6.x86_64
上面有安裝tomcat,mysql,zabbix

最近每天都會當機,可以ssh過去但輸入密碼後就停住,從VMware vSphere Client打開主機會看到錯誤訊息如下
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message
INFO: task xxxx:xxxx blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message
INFO: task xxxx:xxxx blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message
INFO: task xxxx:xxxx blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message
INFO: task xxxx:xxxx blocked for more than 120 seconds.

google後大家的解法都是修改
vm.dirty_ratio=10
vm.dirty_background_ratio=5

但我修改後還是一樣,後來發現是固定每天半夜一點的時候會當機,
查看/var/log/cron 發現都是在一點後時間突然變成錯誤的未來時間?
Jul 17 00:40:01 localhost CROND[25556]: (root) CMD (/usr/lib64/sa/sa1 1 1)
Jul 17 00:50:01 localhost CROND[26726]: (root) CMD (/usr/lib64/sa/sa1 1 1)
Jul 17 01:00:01 localhost CROND[27940]: (root) CMD (/usr/lib64/sa/sa1 1 1)
Jul 17 01:01:01 localhost CROND[28064]: (root) CMD (run-parts /etc/cron.hourly)
Jul 17 01:01:01 localhost CROND[28065]: (root) CMD (run-parts /etc/cron.hourly)
Jul 17 16:46:12 localhost crond[2796]: (CRON) STARTUP (1.4.4)
Jul 17 16:46:12 localhost crond[2796]: (CRON) INFO (RANDOM_DELAY will be scaled with factor 94% if used.)
Jul 17 16:46:12 localhost crond[2796]: (CRON) INFO (running with inotify support)

/var/log/message 的log
Jul 17 16:46:03 localhost kernel: imklog 5.8.10, log source = /proc/kmsg started.
Jul 17 16:46:03 localhost rsyslogd: [origin software="rsyslogd" swVersion="5.8.10" x-pid="1491" x-info="http://www.rsyslog.com"] start
Jul 17 16:46:03 localhost kernel: Initializing cgroup subsys cpuset
Jul 17 16:46:03 localhost kernel: Initializing cgroup subsys cpu
Jul 17 16:46:03 localhost kernel: Linux version 2.6.32-431.el6.x86_64 (mockbuild@x86-023.build.eng.bos.redhat.com) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-4) (GCC) ) #1 SMP Sun Nov 10 22:19:54 EST 2013
Jul 17 16:46:03 localhost kernel: Command line: ro root=/dev/mapper/vg_airtd01-lv_root rd_LVM_LV=vg_airtd01/lv_swap rd_LVM_LV=vg_airtd01/lv_root LANG=zh_TW.UTF-8 rd_NO_MD crashkernel=auto rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
Jul 17 16:46:03 localhost kernel: KERNEL supported cpus:
Jul 17 16:46:03 localhost kernel: Intel GenuineIntel
Jul 17 16:46:03 localhost kernel: AMD AuthenticAMD
Jul 17 16:46:03 localhost kernel: Centaur CentaurHauls
Jul 17 16:46:03 localhost kernel: Disabled fast string operations
Jul 17 16:46:03 localhost kernel: BIOS-provided physical RAM map:
Jul 17 16:46:03 localhost kernel: BIOS-e820: 0000000000000000 - 000000000009f800 (usable)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000000dc000 - 0000000000100000 (reserved)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 0000000000100000 - 00000000bfef0000 (usable)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000bfef0000 - 00000000bfeff000 (ACPI data)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000bfeff000 - 00000000bff00000 (ACPI NVS)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000bff00000 - 00000000c0000000 (usable)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000f0000000 - 00000000f8000000 (reserved)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 00000000fffe0000 - 0000000100000000 (reserved)
Jul 17 16:46:03 localhost kernel: BIOS-e820: 0000000100000000 - 0000000240000000 (usable)
Jul 17 16:46:03 localhost kernel: DMI present.
Jul 17 16:46:03 localhost kernel: SMBIOS version 2.4 @ 0xF6A70
Jul 17 16:46:03 localhost kernel: Phoenix BIOS detected: BIOS may corrupt low RAM, working around it.
Jul 17 16:46:03 localhost kernel: Hypervisor detected: VMware
Jul 17 16:46:03 localhost kernel: last_pfn = 0x240000 max_arch_pfn = 0x400000000
Jul 17 16:46:03 localhost kernel: x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
Jul 17 16:46:03 localhost kernel: total RAM covered: 8192M
Jul 17 16:46:03 localhost kernel: Found optimal setting for mtrr clean up
Jul 17 16:46:03 localhost kernel: gran_size: 64K chunk_size: 64K num_reg: 4 lose cover RAM: 0G
Jul 17 16:46:03 localhost kernel: last_pfn = 0xc0000 max_arch_pfn = 0x400000000
Jul 17 16:46:03 localhost kernel: init_memory_mapping: 0000000000000000-00000000c0000000
Jul 17 16:46:03 localhost kernel: init_memory_mapping: 0000000100000000-0000000240000000
Jul 17 16:46:03 localhost kernel: RAMDISK: 36f82000 - 37fef4e2
Jul 17 16:46:03 localhost kernel: ACPI: RSDP 00000000000f6ac0 00024 (v02 PTLTD )
Jul 17 16:46:03 localhost kernel: ACPI: XSDT 00000000bfef109b 0005C (v01 INTEL 440BX 06040000 VMW 01324272)
Jul 17 16:46:03 localhost kernel: ACPI: FACP 00000000bfefee73 000F4 (v04 INTEL 440BX 06040000 PTL 000F4240)
Jul 17 16:46:03 localhost kernel: ACPI: DSDT 00000000bfef1349 0DB2A (v01 PTLTD Custom 06040000 MSFT 03000001)
Jul 17 16:46:03 localhost kernel: ACPI: FACS 00000000bfefffc0 00040
Jul 17 16:46:03 localhost kernel: ACPI: BOOT 00000000bfef1321 00028 (v01 PTLTD $SBFTBL$ 06040000 LTP 00000001)
Jul 17 16:46:03 localhost kernel: ACPI: APIC 00000000bfef12c3 0005E (v01 PTLTD ? APIC 06040000 LTP 00000000)
Jul 17 16:46:03 localhost kernel: ACPI: MCFG 00000000bfef1287 0003C (v01 PTLTD $PCITBL$ 06040000 LTP 00000001)