Re: LVM RAID 0

[josep lladonosa capell]

Hello, Wink,

What about having a small boot partition outside LVM and RAID0?

Evenmore, you might create a RAID1 for /boot in order to have
redundancy at least for the boot partition.
Another option would be, having 2 /boot partitions (non RAID1),  one
in each NVME device and use the second one as a backup...

Josep


Missatge de Wink Saville <address@hidden> del dia dg., 10 de maig
2020 a les 20:52:
>
> Does grub support using an LVM RAID 0 volume as the boot partition/volume?
>
> What I'm trying to do is install arch linux on a system with 2 nvme
> ssd's, I thought I would try to use LVM (Logical Volume Manager) in
> raid 0 mode and can't get it working. I searched high and low but have
> found no example on the internet where lvm raid 0 was used for a "boot
> partition". So maybe I'm trying something that isn't supported. I
> followed the instructions here:
>
>      https://wiki.archlinux.org/index.php/Install_Arch_Linux_on_LVM
>
>  And it says grub is the only bootloader that works with lvm:
>
>      "Only GRUB is known to support LVM."
>
> In the "Configure mkinitcpio for RAID" it talks about LVM RAID for the
> root filesystem but doesn't mention the boot filesystem, so maybe grub
> doesn't work with boot being on a RAID 0.
>
> Here is an outline of what I've done. I created two physical volumes
> and then one volume group with the two physical volumes and finally
> two logical volumes, boot and root. Both of these are striped across
> the two physical volumes:
>
>     pvcreate --dataalignment 1m /dev/nvme0n1
>     pvcreate --dataalignment 1m /dev/nvme1n1
>     vgcreate vg0 /dev/nvme0n1 /dev/nvme1n1
>     lvcreate --type raid0 -L 2G --stripes 2 --stripesize 64k -n boot vg0
>     lvcreate --type raid0 -L 500G --stripes 2 --stripesize 64k -n root vg0
>
>
> After I got arch linux installed on the chroot I tried to install grub
> but got an error that it couldn't find the disk:
>
>      grub-install: error: disk
> `lvmid/ATeSVR-...-1k0)cs/)tVDsa-...-BU9tqx' not found'
>
> The lvmid corresponds to the "lvmid" syntax of 'lvmid/<volume group
> id>/<logical volume id>" and I verified that the volume group id
> matched that of /dev/vg0 and logical volume id matched /dev/vg0/boot.
>
> -- Wink
>