SLES9 on 16 Core Opteron- Probs

Yohoo!

We are running an Tyan VX50 Server. He has two Mainboards with four
physical pcu slots on each.

Originally it was delivered with four DualCoreOpteron 875 and 8GB of
RAM. There is installed a SLES9 x64 and MySQL 4.1.x. Runs fine.

Now we wanted to upgrade and installed another four 875ers with 2Gig RAM
each.

When we enable all 16CPUs and starting MySQL, there ist a very high
System-Load (up to 50%) and mysql is very slow.

So where is our mistake? Ist there any configuration to get the SLES9
running smothly with 16 cores?

Any hints?

Greets

Christian Völker wrote:
> Yohoo!
> 
> We are running an Tyan VX50 Server. He has two Mainboards with four
> physical pcu slots on each.
> 
> Originally it was delivered with four DualCoreOpteron 875 and 8GB of
> RAM. There is installed a SLES9 x64 and MySQL 4.1.x. Runs fine.
> 
> Now we wanted to upgrade and installed another four 875ers with 2Gig RAM
> each.
> 
> When we enable all 16CPUs and starting MySQL, there ist a very high
> System-Load (up to 50%) and mysql is very slow.
> 
> So where is our mistake? Ist there any configuration to get the SLES9
> running smothly with 16 cores?
> 
> Any hints?
> 
> Greets
> 
> Christian
did you see if you have to do anything in the bios?

Yohoo!
> did you see if you have to do anything in the bios?
> I've seen that on several servers.
For what shoul I look? I didn't see anything to this.

And, all CPUs are found. My SLES shows 16 cpus in /proc/cpuinfo. But
they don't work acceptable :-(

Greets

Christian Völker wrote:
> Yohoo!
> > did you see if you have to do anything in the bios?
> > I've seen that on several servers.
> For what shoul I look? I didn't see anything to this.
>
> And, all CPUs are found. My SLES shows 16 cpus in /proc/cpuinfo. But
> they don't work acceptable :-(
Is powersaved running?
run "cat /proc/cpuinfo" and check if the CPU-speed in Mhz seems to be
reasonable.
Imho there's no need to throttle the CPU's on a server.

I usually disable powersaved when the system is runnig, following these
steps:
1) cat /dev/zero > /dev/null &
2) cat /proc/cpuinfo (you might need to start several instances of
first step to get the CPU's running at full speed.
3) /etc/init.d/powersaved stop
4) insserv -r powersaved
5) kill all the "cat /dev/zero > /dev/null &"

Now the system should be running at full throttle at all times.

Best regards,
Fredrik

> Greets
> 
> Christian

Yohoo!

>> And, all CPUs are found. My SLES shows 16 cpus in /proc/cpuinfo. But
>> they don't work acceptable :-(
> Is powersaved running?
Hmmm... yes, he is running. But it doesn't explain, why it works with 8
cores, but not with 16 cores.

> I usually disable powersaved when the system is runnig, following these
> steps:
Thanks for these hints, I will do it on other servers. But I don't think
it has to do with my problem.