On Mon, Jan 20, 2014 at 11:51:35AM -0500, Calvin Walton wrote: > > Single: When it writes does it simple fill up one drive then move to > > the next or does it write in a round robin type fashion? > > I'm not totally sure, this depends on the vagaries of the chunk > allocator. When writing only new files to an initially blank filesystem, > I would expect this to be a case; but on a used filesystem you will > probably get files fragmented over both disks.
The chunks are sorted by remaining free space, descending, so after some GBs written it will become ~round robin (depending on the device sizes). The 'fill one device first" is addressed by "Btrfs: Add linear chunk allocation support" http://www.spinics.net/lists/linux-btrfs/msg29616.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
