[linux-lvm] Viewing logical/physical mapping when striping
Dax Kelson
dax at gurulabs.com
Wed Jun 30 22:34:41 UTC 2004
On Wed, 30 Jun 2004, David J N Begley wrote:
> Here's where my mind really gets screwed-up - if I throw data at the LVs, the
> read/write pattern tends to indicate that the striping _is_ working, which
> then contradicts the mapping that 'lvdisplay -v' shows!
>
> What's happening? Are LEs always mapped to PEs in a linear fashion whilst
> striping occurs at some lower (per-chunk-of-an-LE) layer?
My understanding that this behaviour you are seeing is coming from the
*filesystem* (ext3, or whatever you are using).
I bet if you used dd, such as:
dd if=/dev/zero of=/dev/VG0/LV0
And watch the write pattern it would be linear.
Dax Kelson
Guru Labs
More information about the linux-lvm
mailing list