[lug] server memory woes (3rd attempt!)

[Michael Belanger]

UPDATE!

After researching the symptoms and consulting with our server's vendor, 
I think I have isolated the problem...

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=121434

the problem is an extremely high iowait on the processors when 
performing IO activities.  For some reason, the Out-of-the-box RHEL 
Kernel is not releasing the IOWAIT after an IO task is run.  It has been 
a known issue with 3-Ware IDE RAID cards and Redhat for some time.  I 
had them change the priority to 'High' and they had since released a 
test kernel that they think may resolve the issue.

Initial testing with the new kernel are promising, but I think I would 
be more confident if the system stays up for a couple weeks without 
incident.

Just thought I'd share the knowledge.

Regards,
-M

John Hernandez wrote:
> Michael Belanger wrote:
> 
>>
>> It is a Western Scientific :
>>
>>  Server Model: WS-2UOPT/3GB (Fusion A64 )
>> motherboard: Arima HDAMA, Dual 100/1000, 8x Memory Slots
>> CPU: (2) Opteron 240, 1.4Ghz
>> System Disk: 80GB 7200 RPM IDE
>> RAID: 8 @ 200GB 7200 RPM SATA Drives
>> Memory: 3GB Registered ECC DDR 333, PC2700, 6x 512MB
>> 3-Ware 8506-8, 8-port SATA RAID Card
>> CDROM
>>
>>
>> The 3-Ware card model number was not listed on the RH suppported 
>> hardware list, but another model similar was.
>>
> 
> I once encountered a similar, seemingly random lockup problem with a 
> dual-Xeon box with a pair of built-in GigE NICs, one of which was a 
> Broadcom.  A bug in the kernel or broadcom driver was the culprit, and 
> we swapped out the mobo for a dual Intel e1000 NIC model.  I believe it 
> was in the RH 8.0 days.
> 
> Have you searched through the RHEL bugs database?  That's how we figured 
> out what was going on.
> 

-- 
+----------------------------------------------------------------------
Michael R. Belanger                    Yahoo!:  darthwonka
DB Programmer                          MSN:     mrbelanger at hotmail.com
                                        Jabber:  mrb at jabber.ciclops.org
"We are the music makers,
And we are the dreamers of dreams.." -Arthur O'Shaughnessy (1844-1881)