On Oct 30, 2014, at 7:30 AM, Zack Coffey <tech42.click...@gmail.com> wrote:
> Rob, That second drive was immediately put to use elsewhere. I figured having > only the metadata on that drive, it wouldn't matter. The data stayed single > and wasn't part of the second drive, only the metadata was. I must not be > capable of understanding why that wouldn't work. single profile means all devices get btrfs chunks. If you do something like: # mkfs.btfs /dev/sda By default you get data profile = single, and metadata profile = DUP. If you then # btrfs add /dev/sdb /mnt/btrfs # btrfs -mconvert=raid1 /mnt/btrfs you now have a volume that is data = single and metadata = raid1. The way the allocator works is that it will first allocate 1GiB data chunks to the device with the most free space remaining, so if that's /dev/sdb it will allocate 1GiB data chunks there until free space is the same for both sda and sdb. And once they have equal space btrfs allocates 1GiB data chunks alternating sda and sdb. Single profile doesn't mean only one device gets data chunks. Is that the misunderstanding? Chris Murphy-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
