On Wed, Feb 18, 2009 at 1:44 AM, Rajesh Kumar Mallah
<mallah.rajesh@gmail.com> wrote:
>>> 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.
excellent. and yes, you have to dump and reload from 32 to 64 bit.