On Thu, Feb 19, 2015 at 7:30 AM, Konstantinos Skarlatos <k.skarlatos@xxxxxxxxx> wrote: > Systemd 219 now sets the special FS_NOCOW file flag for its journal > files[1]. This unfortunately breaks the ability to repair the journal on > RAID 1/5/6 btrfs volumes, should a bad sector happen to appear there. Is > this something that can be configured for systemd? Is btrfs going to someday > fix the fragmentation problem, making this option reduntant? Chris is looking at a per file autodefrag setting, last I read. I think that's a better way forward. I'm finding that +C on journals is an OK short term workaround; the problem is that if the containing subvolume is subject to snapshots, in effect the +C benefit is thwarted. I have a ~2 week old journal subject to merely 6 snapshots in that time, and it has over 9000 extents despite +C. I think autodefragging journals on HDD is OK, but I'm uncertain if this is really necessary on SSD. I'm not sure how to make this better without adding complexity. I just had an idea of a journal specific partition which kinda decouples the dependency on filesystems being mounted so the journal can persistently write to stable media earlier in boot and later in shutdown, and some other things are easier for journald also. But it might make some people scream. -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
