Re: H800 + md1200 Performance problem

On Tue, Apr 3, 2012 at 9:32 AM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> wrote:
> On Tue, Apr 3, 2012 at 6:20 AM, Cesar Martin <cmartinp(at)gmail(dot)com> wrote:
>> Hello there,
>>
>> I am having performance problem with new DELL server. Actually I have this
>> two servers
>>
>> Server A (old - production)
>> -----------------
>> 2xCPU Six-Core AMD Opteron 2439 SE
>> 64GB RAM
>> Raid controller Perc6 512MB cache NV
>>   - 2 HD 146GB SAS 15Krpm RAID1 (SO Centos 5.4 y pg_xlog) (XFS no barriers)
>>   - 6 HD 300GB SAS 15Krpm RAID10 (DB Postgres 8.3.9) (XFS no barriers)
>>
>> Server B (new)
>> ------------------
>> 2xCPU 16 Core AMD Opteron 6282 SE
>> 64GB RAM
>> Raid controller H700 1GB cache NV
>>   - 2HD 74GB SAS 15Krpm RAID1 stripe 16k (SO Centos 6.2)
>>   - 4HD 146GB SAS 15Krpm RAID10 stripe 16k XFS (pg_xlog) (ext4 bs 4096, no
>> barriers)
>> Raid controller H800 1GB cache nv
>>   - MD1200 12HD 300GB SAS 15Krpm RAID10 stripe 256k (DB Postgres 8.3.18)
>> (ext4 bs 4096, stride 64, stripe-width 384, no barriers)
>>
>> Postgres DB is the same in both servers. This DB has 170GB size with some
>> tables partitioned by date with a trigger. In both shared_buffers,
>> checkpoint_segments... settings are similar because RAM is similar.
>>
>> I supposed that, new server had to be faster than old, because have more
>> disk in RAID10 and two RAID controllers with more cache memory, but really
>> I'm not obtaining the expected results
>
> What does
>
> sysctl -n vm.zone_reclaim_mode
>
> say?  If it says 1, change it to 0:
>
> sysctl -w zone_reclaim_mode=0

That should be:

sysctl -w vm.zone_reclaim_mode=0