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