[CentOS] Installing on LVM on SW-RAID

Hello list,

I'm trying to install CentOS 5.2 on LVM on a SW-RAID level 1, but I'm unable to understand how to use the installer correctly.

What I'm trying to do is emulate something I've already done with another distro where:

sda5 \ RAID1 --> /boot sdb5 /

sda6 \ RAID1 --> LVM --> /root, /home, /usr, /var... etc. sdb6 /

I've succesfully created the raid, and the PV for LVM, but I can't figure out how to create a VG inside the PV.

Is it possible using the installer, or should I better install it using one disk, and once installed create the raid/pv/vg, and move everything around by hand?

Many thanks in advance, Norberto