Re: btrfs raid configuration vs mdraid

[Fredrik Salomonsson]

Hi Giovanni,

Giovanni Biscuolo <address@hidden> writes:

> Hello Guix!
>
> My preferred storage setup until now was using RAID-1 software RAID
> built with mdadm; for a new machine I'm considering setting up a RAID-1
> btrfs volume as root, but I have much less experience with btrfs
>
> Assuming I'm going to format the root filesystem as:
>
>   mkfs.btrfs -m raid1 -d raid1 /dev/sda3 /dev/sdb3
>
> how should I configure (file-system...)? this way:
>
> (file-system
>   (mount-point "/")
>   (type "btrfs")
>   (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
>
> with UUID taken from "lsblk -f"?

That should work. Creating a label will also work and might be easier to
handle as you won't need to update the config file incase you reformat your
disks. One thing you should note is that guix might generate incorrect
paths for grub if you are using subvolumes. At least guix < 1.0 does
that for me, haven't tested 1.0+ yet. But I have been using a shell
script that works around that issue.

> From you experience is RAID on brtfs as solid as the one on mdadm?

I have very little experience with mdadm, so can only speak of my
experience with btrfs and RAID-1. Which I have been using for 3+ years.
For me it has been solid. Only issue I have encountered was when my
fileserver lost power a few times leaving the filesystem corrupt. A
"btrfs check --repair" fixed that issue.

--
s/Fred[re]+i[ck]+/Fredrik/g

fix-grub.sh
Description: Script for fixing broken paths in grub after guix reconfigure

config.scm
Description: Guix configuration