More LVM questions

[Philip Prindeville]

Paul Howarth wrote:

>On Thu, 2005-08-04 at 00:55 -0600, Philip Prindeville wrote:
>  
>
>>If I just got an identical disk to /dev/sda (as /dev/sdb), and I want to
>>create an identical /dev/sdb2 partition (to /dev/sda1) in size,
>>    
>>
>
>Use fdisk to create a partition with the same number of cylinders as
>sda1.
>
>  
>
>>then
>>create a logical volume as LogVol01 that's identical in size and
>>properties to LogVol00 (which was created by the default install
>>procedures) and then add it to VolGroup00, what are the steps
>>to do this?
>>    
>>
>
>Create a physical volume on sdb2:
># pvcreate /dev/sdb2
>
>Add sdb2 to Volume Group VolGroup00:
># vgextend VolGroup00 /dev/sdb2
>
>Get details of LogVol00 (particularly size in extents (LE)):
># lvdisplay /dev/VolGroup00/LogVol00
>
>Create LogVol01 with same size (n):
># lvcreate --extents n --name LogVol01 VolGroup00
>
>That should do it. The default LogVol00 won't have any "special" options
>and will fill the original partition sda1, so this procedure should
>result in what you're after.
>
>However, do you really want a separate logical volume rather than
>extending LogVol00 to make it bigger?
>
>Paul.
>  
>

I was thinking that if the logical volumes are separate then there is
the possibility of parallelizing atomic operations (like journaling,
deletions, etc) that would result in better performance.

Likewise, doing a filesystem check after a crash can run in parallel
on both volumes...

-Philip