Re: [linux-lvm] lvm2 weirdness on software RAID5

[Michael Ossmann <mike ossmann com>]

On Wed, Apr 07, 2004 at 03:55:33PM -0700, Clint Byrum wrote:
> 
> mdadm --create /dev/md2 --chunk 256 --level 5 -n 4 /dev/hdc1 /dev/hdd1
> /dev/hdg1 /dev/hdh1
<snip>
> [root backup root]# lvm pvcreate /dev/md2
<snip>
> [root backup root]# lvm pvs
> PV         VG      Fmt  Attr PSize   PFree
> /dev/hdc1          lvm2 --   335.37G 335.37G
> /dev/md0   backups lvm2 a-   349.33G      0
> /dev/md1   backups lvm2 a-   349.31G   8.64G

Looks like lvm is configured to allow both /dev/md* and
/dev/hd* as physical devices.  You probably want to limit it
to /dev/md* so that it doesn't get confused by things it
finds on the raw disk partition devices.  You can do this
with:

  filter = [ "r|^/dev/hd*|" ]

in the devices block of your /etc/lvm/lvm.conf.  If you do
not have an /etc/lvm/lvm.conf, you can copy the sample
config in the lvm2 distribution or create a fresh one with:

  # lvm dumpconfig > /etc/lvm/lvm.conf

You could also make the filter more specific if you want:

  filter = [ "r|^/dev/hdc*|" ]

mossmann