I was thinking of simulating L2ARC like design from ZFS for btrfs. that's why I wanted one ssd partition taking care of both mirrored drives, mostly for read cache. thanks for your reply. pavol On Mon, Dec 16, 2013 at 2:11 AM, Matthew Patton <pattonme@xxxxxxxxx> wrote: > On Sun, 15 Dec 2013 20:01:57 -0500, Pavol Cupka <pavol.cupka@xxxxxxxxx> > wrote: > >> I would like to use a bcache for btrfs filesystem residing on two >> identical disk as raid1 using btrfs' raid (without soft/hard raid). >> >> Is it possible? > > > if I understood you correctly, no. > > >> I would like to use the same ssd/ssd partition for caching both >> drives/mirror. Is this doable? > > > You will have to build the btrfs 'raid' on top of two bcache devices. If the > caching device for both devices in the same SSD (partitioned) what's the > point? Assuming Btrfs has a similar feature set to MD's Raid1 write-mostly, > you could accelerate the one side, and run the other half of the mirror > without acceleration. Otherwise I would just use MD's Raid1 and be done with > it. Put btrfs/ext4/xfs on top as you like. > > Does your intended workload really benefit from putting an SSD into the mix? -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
