[linux-lvm] LVM2 seems to chop performance by 33%

[David Greaves]

Alasdair G Kergon wrote:

>On Sun, Jun 20, 2004 at 07:17:58PM +0100, David Greaves wrote:
>  
>
>>No-one ever replied as to why blockdev --setra / --getra is not the same 
>>as that displayed in lvdisplay
>>And it's not documented that I can find. There's a comment: "Not used by 
>>device-mapper." And that means.....?
>>    
>>
>
>Any LVM read ahead setting is ignored by LVM2 i.e. not passed to the kernel.
>
>If it's demonstrated to be useful it could still be implemented, but
>the current development priorities are still correctness and new features 
>rather than performance.
>
>Alasdair
>  
>
Thanks Alasdair

It would be good to modify the docs to be clearer and maybe say "use 
blockdev --setra"

David