[linux-lvm] LVM and *bad* performance (no striping)

[Rik van Riel]

On Mon, 26 Feb 2001, Jorg de Jong wrote:

> here are my stats... (be your owen judge....)

> [root] /root > time dd if=/dev/hde of=/dev/null count=100000
> 100000+0 records in
> 100000+0 records out
> 0.200u 1.050s 0:03.95 31.6%	0+0k 0+0io 116pf+0w
>
> [root] /root > time dd if=/dev/vg00/vm of=/dev/null count=100000
> 100000+0 records in
> 100000+0 records out
> 0.160u 0.860s 0:02.92 34.9%	0+0k 0+0io 116pf+0w

Interesting, so LVM actually takes a full second LESS to
read in the same data ...

Maybe LVM does some device-level readahead to speed things
up ?

regards,

Rik
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