CentOS - Oct 2009 - Disc layout advice

I have a DAS w/ 6 750Gb and 6 1Tb discs I am setting up using Linux raid.
The controller is a POS so each disc is exported as an R0 single volume.

I used a parted and fdisk script to create 1 max size partition labeled as
Linux Raid Autodetect and created the first r6 array w/ mdadm. I normally
create and mark partitions as raid or lvm so people know what's going on.

The first md array is obviously too large for fdisk and parted doesn't
create
lvm partitions does it?

Should I just pvcreate the raw /dev/md0 and not worry about creating an lvm
partition on it, or should/(can?) I?

Thanks!
jlc

On Tue, Oct 06, 2009 at 05:28:46PM +0000, Joseph L. Casale
wrote:
> Should I just pvcreate the raw /dev/md0 and not worry about creating an lvm
> partition on it, or should/(can?) I?
pvcreate is the first step of creating LVM areas.   If you're not going
to use LVM then you don't need to pvcreate.   However I recommend
that you _do_.

Typically the steps are:
  mdadm to create the array  (you've already done that)
  pvcreate the disk (/dev/md0)
  vgcreate a volume group, with /dev/md0 in it
  lvcreate the logical volumes inside the volume group

eg
  pvcreate /dev/md0
  vgcreate MyVolumeGroup /dev/md0
  lvcreate -L 1T MyVolumeGroup MyLVol1
  lvcreate -L 1T MyVolumeGroup MyLVol2
  lvcreate -L 1T MyVolumeGroup MyLVol3
would create 3 1Terabyte logical volumes which could be accessed as
/dev/MyVolumeGroup/MyLVol1 etc etc.  They're what you could run mke2fs
on and mount.

(commands off the top of my head, so might be slightly wrong!)

-- 

rgds
Stephen