btrfs raid1 boot root etc.

Efka · 2024-08-27 08:52:06

How should i approach it ?
I want to use raid1 for my boot root home snapshot device. will use 2x ssd.
do i need to replicate each step for each disk and add each disk uuid in fstab ?
or using this enough to add one uuid ?

 mkfs.btrfs -d raid1 -m raid1 /dev/part1 /dev/part2

And how btrfs raid 1 works ? i see it says single ( arch wiki ) - metadata is mirrored but data is no , raid1 and data is not mirrored ? or i misunderstand something ? does my command which is missing single mirrors metadata and data ? if i want to have 1 disk redundancy i need to have mirrored data and metadata right ?
From wikipedia:

RAID 1 consists of an exact copy (or mirror) of a set of data on two or more disks; a classic RAID 1 mirrored pair contains two disks. This configuration offers no parity, striping, or spanning of disk space across multiple disks, since the data is mirrored on all disks belonging to the array, and the array can only be as big as the smallest member disk. This layout is useful when read performance or reliability is more important than write performance or the resulting data storage capacity.[13][14]
The array will continue to operate so long as at least one member drive is operational.[15]

I want to have 1disk redundancy with boot / root / home /snapshot partitions then have a zfs for rest of my drives and have a cron job(?) where i send my snapshot to my external usb drive ( zfs ) [ my externald hdd is zfs due to usage on my FreeBSD laptop and another PC dont have windows, i want to have zfs . period I think i cant have zfs at the moment for 6.10 kernel ( if i did my re-search correctly ) .
]
I need btrfs for main system due to i have Arch on my VPS and its btrfs. ( trying to replicate so i could easily do stuff on my VPS what i did on my WS )

And how i should approach boot ? using uefi and trough my research grub is best for it as its supports multiple device booting and do i need to add degraded to avoid future extra steps to boot if 1 ssd fails ?
I wont have encryption for sake of simplicity to boot.

lenhuppe · 2024-08-31 19:03:48

Creating mirrors in btrfs may be different from other filesystems you have used. When you are finished creating the mirror you only need to mount one of the two mirrored partitions.

mkfs.btrfs -L broot -O free-space-tree -m raid1 -d raid1 /dev/nvme0n1p2 /dev/nvme1n1p2
mount -t btrfs /dev/nvme0n1p2 /mnt

Next you can create sub-volumes:

btrfs subvolume create /mnt/@
btrfs subvolume create /mnt/@home
btrfs subvolume create /mnt/@archive

Lastly you remount:

umount -R /mnt
mount -t btrfs -o noatime,compress=zstd,ssd,discard=async,autodefrag,subvol=@ /dev/nvme0n1p2 /mnt
mount -t btrfs -m -o noatime,compress=zstd,ssd,discard=async,autodefrag,subvol=@home /dev/nvme0n1p2 /mnt/home
mount -t btrfs -m -o noatime,compress=zstd,ssd,discard=async,autodefrag,subvol=@archive /dev/nvme0n1p2 /mnt/archive

When you are ready you can run genfstab as you normally would.

Hope that clarifies the process for you.

Arch Linux

#1 2024-08-27 08:52:06

btrfs raid1 boot root etc.

#2 2024-08-31 19:03:48

Re: btrfs raid1 boot root etc.

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