Advice on what dmsetup/fdisk/lvm does!

[Ian Chapman]

On 13/10/09 18:33, Dan Track wrote:

> sda and sdb are the same, as there is only one disk but two separate
> paths to it, so it shows up twice under different device mappings.
>
> My question now is after restarting mutlipathd, what is the next step?
>
> Do I need to use dmsetup, searching the web I still can't understand
> why I need it.
>
> I'm looking to create a logical volume on this disk. Once multipath is
> working should I only see one entry in /proc/partitions, instead of
> /dev/sda and /dev/sdb?

Posting your configuration file will probably help, but you don't need 
to touch /dev/sda or /dev/sdb. There should be an entry under 
/dev/mapper (eg /dev/mapper/SANVOL) or whatever you called it, which is 
the device you use to create the filesystems, logical volumes, 
partitions etc. You'll still see /dev/sda and /dev/sdb in 
/proc/partitions though.

It's also recommended you exclude lvm (/etc/lvm/lvm.conf) from looking 
at /dev/sda and /dev/sdb, otherwise there's the potential to confuse it.



-- 
Ian Chapman.