Re: Tuning Tips for a new Server

On Aug 17, 2011, at 8:41 AM, Andy Colson wrote:

> On 8/16/2011 8:35 PM, Ogden wrote:
>> Hope all is well. I have received tremendous help from this list prior and therefore wanted some more advice.
>>
>> I bought some new servers and instead of RAID 5 (which I think greatly hindered our writing performance), I configured 6 SCSI 15K drives with RAID 10. This is dedicated to /var/lib/pgsql. The main OS has 2 SCSI 15K drives on a different virtual disk and also Raid 10, a total of 146Gb. I was thinking of putting Postgres' xlog directory on the OS virtual drive. Does this even make sense to do?
>>
>> The system memory is 64GB and the CPUs are dual Intel E5645 chips (they are 6-core each).
>>
>> It is a dedicated PostgreSQL box and needs to support heavy read and moderately heavy writes.
>>
>> Currently, I have this for the current system which as 16Gb Ram:
>>
>> max_connections = 350
>>
>> work_mem = 32MB
>> maintenance_work_mem = 512MB
>> wal_buffers = 640kB
>>
>> # This is what I was helped with before and made reporting queries blaze by
>> seq_page_cost = 1.0
>> random_page_cost = 3.0
>> cpu_tuple_cost = 0.5
>> effective_cache_size = 8192MB
>>
>> Any help and input is greatly appreciated.
>>
>> Thank you
>>
>> Ogden
>
> What seems to be the problem? I mean, if nothing is broke, then don't fix it :-)
>
> You say reporting query's are fast, and the disk's should take care of your slow write problem from before. (Did you test the write performance?) So, whats wrong?

I was wondering what the best parameters would be with my new setup. The work_mem obviously will increase as will everything else as it's a 64Gb machine as opposed to a 16Gb machine. The configuration I posted was for a 16Gb machine but this new one is 64Gb. I needed help in how to jump these numbers up.

Thank you

Ogden