On Mon, Feb 16, 2015 at 10:48 AM, Eliezer Croitoru <eliezer at ngtech.co.il> wrote: > Thanks Chris for the detailed response! > > I couldn't understand the complex sentence about XFS and was almost > convinced that XFS might offer a new way to spread across multiple disks. It's not new in XFS, it's behaved like this forever. But it's new in that other filesystems don't allocate this way. I'm not aware of any other filesystem that does. Btrfs could possibly be revised to do this somewhat more easily than other fs's since it also has a concept of allocation chunks. Right now its single data profile allocates in 1GB chunks until full, and the next 1GB chunk goes on the next device in a sequence mainly determined by free space. This is how it's able to use different sized devices (including raid0,1,5,6). So it can read files from multiple drives at the same time, but it tends to only write to one drive at a time (unless using one of the striping raid-like profiles). -- Chris Murphy