RAID5 over LVM on Ubuntu Server 12.04.3
- by April Ethereal
I'm trying to create a RAID5 software array using LVM. I use VirtualBox as I'm only learning how LVM works. So I've created 4 virtual SCSI drives and then did the following:
pvcreate /dev/sd[b-e]
vgcreate /dev/sd[b-e] raid5_vg
lvcreate --type raid5 -i 3 -L 1G -n raid_lv raid5_vg
However, I get an error after the last command:
WARNING: Unrecognised segment type raid5
Using default stripesize 64.00 KiB
Rounding size (256 extents) up to stripe boundary size (258 extents)
Cannot update volume group raid5_vg with unknown segments in it!
So it looks like raid5 is not a valid segment type. "lvm segtypes" also doesn't contain 'raid5' entry:
root@ubuntu-lvm:~# lvm segtypes
striped
zero
error
free
snapshot
mirror
So my question is - how could I create RAID5 logical volume using LVM only? It seems that it is possible, I saw a few references (not for Ubuntu, unfortunately) for RedHat and Gentoo systems. I don't want to use mdadm for now, until I find out that it is mandatory.
Some info about my system is below:
root@ubuntu-lvm:~# uname -a
Linux ubuntu-lvm 3.8.0I use Ubuntu Server 12.04.3 (i686)-29-generic #42~precise1-Ubuntu SMP Wed Aug 14 15:31:16 UTC 2013 i686 i686 i386 GNU/Linux
root@ubuntu-lvm:~# dpkg -l | grep lvm
ii lvm2 2.02.66-4ubuntu7.3 The Linux Logical Volume Manager
Thanks.
