[Discuss] btrfs

[Dan Ritter]

On Mon, Feb 25, 2013 at 07:11:13PM +0000, Edward Ned Harvey (blu) wrote:
> All of this distinction between raid0, mirroring, raid10, in context of btrfs, is irrelevant, because it's true for straight-up traditional RAID, which is not what's happening in btrfs or zfs.

You are incorrect about what is happening.


> In btrfs and zfs, it goes like this:
> mirror dev0 dev1 dev2
> or
> raid1 dev0 dev1 dev2
> This makes a 3-way mirror.  Total usable capacity of a single disk, triple redundant.

This is incorrect for btrfs. Assuming 3 identical devices, btrfs
raid1 creates a 2-way replication with a capacity of 1.5x a
single device.

http://permalink.gmane.org/gmane.comp.file-systems.btrfs/17183

http://www.spinics.net/lists/linux-btrfs/msg15867.html

-dsr-