Re: [noob q. on block layer] block IO read-ahead during sequential *write*?

["Frantisek Rysanek" <Frantisek.Rysanek@post.cz>]

On 7 Jan 2008 at 13:49, Jörn Engel wrote:
>
> If you retry the dd with bs=4096 (or whatever your architecture's page
> size happens to be), does this still occur?
> 
> JĂśrn
> 
wow, thanks, it works, this is so obvious.
I tend to use values like bs=512000 or suchlike, but probably never
stroke this particular value when I was looking at iostat.
Must've missed that modulo 4096 somehow.

Seems like cp is using 512B per transaction, judging by how slow the
transfer goes. If I use bs=500000 or even bs=1024, it goes faster.

Have a nice day :-}

Frank Rysanek