On Tuesday June 26, nodes@xxxxxxxxxxx wrote: > Neil Brown wrote: > > > > Sounds a lot like "RAIF" - ask google for details. > > I did not know about RAIF. RAIF "merges" separate filesystems? That is a > good idea in itself. > > My idea is for driver that provides a filesystem from image files it > controls. Because it knows these resources it uses access in tandem to > attain performance. ??? (reads original description in more detail). So... the filesystem images are identical in both copies, and the "interesting" bit is that the image is just a file on some filesystem. So could I implement your idea by: dd if=/dev/zero of=/1/bigfile count=lotsandlots dd if=/dev/zero of=/2/bigfile count=lotsandlots losetup /dev/loop1 /1/bigfile losetup /dev/loop2 /2/bigfile mdadm -C /dev/md0 --level=raid1 --raid-disks=2 /dev/loop1 /dev/loop2 mkfs /dev/md0 mount /dev/md2 /space ?? Why would you bother? Well, I do it a lot of code testing, but I would be hard pressed to make a case for that sort of config in production. You said: > 1) the disks need > not be the same size or from the same manufacturer; 2) the supporting code > would be cross-platform. md/raid already works happily with different sized drives from different manufacturers (for raid1, it only uses as much space as the smaller drive provides, For raid0 it uses it all). I don't know what you mean by '2'. So I still cannot see anything particularly new. What am I missing? NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
