Re: Linux LowMem errors

Not that MTU! There's an Oracle patch which has the following effect

change skgxp MTU from 32k to 16k

What seems to be happening is that Oracle requests 32k chunks of memory from the OS for (I think) IPC packets. The bug description suggests that Linux is somewhat prone to low memory fragmentation and isn't able to allocate the memory.

 On Feb 10, 2008 3:59 PM, Tim Gorman <tim_at_evdbt.com> wrote:

 MTU of 32768 sounds interesting -- usually it is set to 1500, occasionally
> 9000. Not sure if this is significant, and I could be misinterpreting
> "requirement" for "setting" or some such, but I thought worth noting...
>
>
>
>
> Niall Litchfield wrote:
>
> We've recently updated some of our RH database servers to kernel
> 2.4.21-53ELHugemem and have experienced problems with the databases and
> ASM instances crashing and huge numbers (like 80,000) yesterday on one box
> of core dumps. The crashes did not occur immediately after the kernel
> update, but that is AFAIK the only significant recent change. The head of
> the trace reads
>
>
> SKGXPVFYMMTU: Could not create context which satisfies the minimum
>
> MTU requirement of 32768 bytes
>
> kgefec: fatal error 0
>
> *** 2008-02-09 07:29:39.767
>
> ksedmp: internal or fatal error
>
> ORA-00603: ORACLE server session terminated by fatal error
>
> ORA-27504: IPC error creating OSD context
>
> ORA-27300: OS system dependent operation:sendmsg failed with status: 12
>
> ORA-27301: OS failure message: Cannot allocate memory
>
> ORA-27302: failure occurred at: sskgxpsnd1
>
> which looks significantly like the issue addressed in Note 419871.1. to
> me. Has anyone else come across these issues?
> --
> Niall Litchfield
> Oracle DBA
> http://www.orawin.info
>
>

-- 
Niall Litchfield
Oracle DBA
http://www.orawin.info

--
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