Messages in this thread | | | From | "Frantisek Rysanek" <> | Date | Mon, 07 Jan 2008 16:51:22 +0100 | Subject | Re: [noob q. on block layer] block IO read-ahead during sequential *write*? |
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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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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