system blackscreen/freeze over ubuntu 11.04.

[fishown]

hello everyone,

Recently my server is crashing spontaneously, It happens around three times a day.
I couldn't find the problem and I will be grateful if you can assist me.

Tech spec:

OS: Ubuntu 11.04
Proccessor: Intel xeon x3450b quadcore 2.66 ( shows 8 cores on logs, wierd)
Ram: 8Gm (dont remember the brand, if its critical i will update)
HDD: WD 2TB Black (x2)
XXX: no graphic interface (so its not video driver.)

additional information:
-when the system freeze I can't log in thought ssh, the server stop to respond.

-I used disc-scan, no errors
-Memtest 86+ (v.4.1) no errors
-replaced the ram once
-replaced OS (from centOS to Ubuntu)
-updated to the newest kernel
-the log stops in the sec the server is freezing with no errors.
-i've closed every program separately, still freezing.

Log that I created with cron(one min before the crash):
____________________________________data block________________________________________
16:17:01 up 1 day, 19:04, 2 users, load average: 3.69, 3.51, 3.15

Linux 2.6.18-238.9.1.el5 (cssc.co.il) 05/19/11 16:17:01
CPU %user %nice %system %iowait %steal %idle 16:17:02
all 27.68 0.00 5.74 0.25 0.00 66.33
Average: all 27.68 0.00 5.74 0.25 0.00 66.33

total used free shared buffers cached Mem:
7974 7749 224 0 137 5227
-/+ buffers/cache:
2384 5590
Swap: 9983 0 9983

______________________________end of data block __________________________________________

____________________________________data block________________________________________
16:18:01 up 1 day, 19:05, 2 users, load average: 3.35, 3.43, 3.14

Linux 2.6.18-238.9.1.el5 (cssc.co.il) 05/19/11 16:18:01
CPU %user %nice %system %iowait %steal %idle 16:18:02
all 32.17 0.00 6.63 0.00 0.00 61.20
Average: all 32.17 0.00 6.63 0.00 0.00 61.20

total used free shared buffers cached Mem:
7974 7764 210 0 138 5238
-/+ buffers/cache:
2387 5587
Swap: 9983 0 9983

______________________________end of data block __________________________________________

[LinuxSecurity]

Find a CPU burn in program and see if the system locks up. Also, check your CPU cooling fan and make sure your system is not overheating.

-- Eric

[fishown]

What do you mean by " CPU burn" ? Please speak with less complicated terms...thank you.

[hatebreed]

cpu burn is a term used to describe a program that will stress your cpu for a designated period of time. you can download one through synaptic or ubuntu software center. I would agree that the cpus may be overheating. How long have you been running your system and how long has this been happening? if it just started then it could also be a motherboard issue too.