Re: Raid 10 chunksize

Mark Kirkwood wrote:
> Rebuilt with 256K chunksize:
>
> transaction type: TPC-B (sort of)
> scaling factor: 100
> number of clients: 24
> number of transactions per client: 12000
> number of transactions actually processed: 288000/288000
> tps = 942.852104 (including connections establishing)
> tps = 943.019223 (excluding connections establishing)
>

Increasing checkpoint_segments to 96 and decreasing 
bgwriter_lru_maxpages to 100:

transaction type: TPC-B (sort of)
scaling factor: 100
number of clients: 24
number of transactions per client: 12000
number of transactions actually processed: 288000/288000
tps = 1219.221721 (including connections establishing)
tps = 1219.501150 (excluding connections establishing)

... as suggested by Greg (actually he suggested reducing 
bgwriter_lru_maxpages to 0, but this seemed to be no better). Anyway, 
seeing quite a reasonable improvement (about 83% from where we started). 
It will be interesting to see how/if the improvements measured in 
pgbench translate into the "real" application. Thanks for all your help 
(particularly to both Scotts, Greg and Stef).

regards

Mark