Alan McKinnon wrote:
On Mon, 19 Sep 2011 13:51:03 +0700
Pandu Poluan<[email protected]> wrote:
On Sep 19, 2011 11:12 AM, "Dale"<[email protected]> wrote:
Peter Humphrey wrote:
On Saturday 17 September 2011 12:34:54 Dale wrote:
Does LVM make the heads move around more or anything like that?
I'm
just thinking it would depending on what lv are on what drives. I
dunno, just curious.
I haven't thought about that, but my first impression is that LVM
won't
make any great difference. The data get stored where the data get
stored, if you see what I mean. How they're organised is in the
implementation layers. (Am I making sense? It's getting late here.)
--
Rgds
Peter Linux Counter 5290, 1994-04-23
Yea, I see the point. I was even thinking that if LVM is on
multiple
drives and the a lv was spanned across two or more drives, then it
could even be faster. Data spanned across two or more drives could
result in it reading more data faster since both drives are
collecting data at about the same time.
But then again, it depends on how the data is spread out too. I
guess it
is six of one and half a dozen of the other.
I'm not sure if LVM by itself implement striping. Most likely not
because LVM usually starts with 1 HD then gets additional PVs added.
Plus there's the possibility that the second PV has a different size.
I might be wrong, though, since all my experience with LVM involves
only one drive.
LVM does do striping according to the man page. I've never tried it,
mostly because LVM is the wrong place to do that IMHO.
Use RAID for that instead and leave LVM to do what it's good at -
managing storage volumes
What I was thinking about is this. You have two drives that is one lv.
It has to be data stored on both drives at some point. Example, you
have a data base that is 500Gbs. You have two drives that are 300Gbs
each that are in the same lv. Well obviously 200Gbs has to be on a
different drive. Isn't that striping which would would result in a
speed increase?
Now if it is like me and is only one drive, then that won't happen.
Dale
:-) :-)
