Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller - Mailing list pgsql-performance

>> Effect of ReadAhead Settings
>> disabled,256(default) , 512,1024
>>
SEQUENTIAL
>> xfs_ra0                 414741 ,   66144
>> xfs_ra256            403647,  545026                 all tests on sda6
>> xfs_ra512            411357,  564769
>> xfs_ra1024          404392,  431168
>>
>> looks like 512 was the best setting for this controller
>
> That's only known for sequential access.
> How did it perform under the random access, or did the numbers not
> change too much?

RANDOM SEEKS /sec

xfs_ra0                  6341.0
xfs_ra256           14642.7
xfs_ra512           14415.6
xfs_ra1024        14541.6

the value does not seems to be having much effect
unless its totally disabled.

regds
mallah.


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