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From:Johnny Withers Date:May 4 2012 3:47pm
Subject:Re: InnoDB and Memory Allocation
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Wow, I hope this hasn't been hanging out in the mysql list server for a
year.

I completely forgot about this problem. Thanks for the info though. I've
been running this server with overcommit_memory=0 and a 42GB buffer pool
for a while now.

Thanks again!


On Fri, May 4, 2012 at 9:38 AM, Charles Cazabon <
charlesc-mysql.com@stripped> wrote:

> Johnny Withers wrote:
>
> > I hope someone can help me out here. I'm having trouble with some new
> > servers and memory allocation.
> >
> > Some basic specs on the servers:
> > 32GB total mem
> > 2GB swap
> > 64-bit RHEL
> > 64-bit mysqld
> > overcommit_memory=2
> >
> > mysql fails to start with 14GB innodb_buffer_pool_size
> > mysql will start with 12GB buffer pool setting
> > When overcommit_memory is set to 0, mysql starts with 26GB buffer pool.
>
> This is due to a system-wide limitation on the amount of memory that can be
> allocated by processes that the Linux kernel imposes when overcommit is
> disabled.  The limit is (amount of swap) + (percentage of physical memory),
> and the default percentage is 50.
>
> So the limit in your case is 2G + 16G == 18G for all processes together;
> 14G
> for innodb_buffer_pool_size is too much.
>
> You can increase the amount of swap, or increase the percentage (via
> /proc/sys/vm/overcommit_ratio, which isn't as well-known, though it is in
> the
> kernel documentation).
>
> Hope that helps.
>
> Charles
>
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-- 
-----------------------------
Johnny Withers
601.209.4985
johnny@stripped

Thread
InnoDB and Memory AllocationJohnny Withers20 Apr
  • Re: InnoDB and Memory AllocationCharles Cazabon4 May
    • Re: InnoDB and Memory AllocationJohnny Withers4 May