RE: Volume Managers in Linux
BERNARD Sebastien (sebastien.bernard@cegetel.fr)
Wed, 4 Nov 1998 14:34:59 +0100
> ----------
> De : Greg Mildenhall[SMTP:greg@networx.net.au]
> Date : mercredi 4 novembre 1998 06:13
> A : James Fidell
> Cc : linux-kernel@vger.rutgers.edu
> Objet : Re: Volume Managers in Linux
>
> On Tue, 3 Nov 1998, James Fidell wrote:
> For example[1]: the ext2 driver will always try to put a data block as
> close to it's inode as possible. If block x is holds the inode, and
> block
> x+1 is free, the driver will plonk data there more often than not. But
> if
> block x and block x+1 are on different physical devices, much of the
> advantage in this is lost. If the filesystem driver has a way of
> knowing
> that there is a device boundary after block x, it will perhaps look at
> x-1
> instead.
>
One solution to cope with such problem without touching the ext2
code is to make the block number of one partition not adjacent to the
other.
Let's I have partition 0 and 1 wich are on two different disks
partition 0 is 20000 block long and partition 1 is 5000 block
long.
The numerotation of the the resulting partition could be :
Block from 0 to 20000 belong to partition 0 and block from
105000 to 110000 belong to partition 1. So two blocks that are not on
the same partition/disk/whatever couldn't get adjacent numbers
logically.
Seb
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/