On Thu, Jul 13, 2017 at 4:32 PM, Liu Bo <bo.li.liu@xxxxxxxxxx> wrote: > On Thu, Jul 13, 2017 at 02:49:27PM -0600, Chris Murphy wrote: >> Has anyone been working with Docker and Btrfs + overlayfs? It seems >> superfluous or unnecessary to use overlayfs, but the shared page cache >> aspect and avoiding some of the problems with large numbers of Btrfs >> snapshots, might make it a useful combination. But I'm not finding >> useful information with searches. Typically it's Btrfs alone vs >> ext4/XFS + overlayfs. >> >> ? > > Is there a reproducer for problems with large number of btrfs > snapshots? No benchmarking comparison but it's known that deletion of snapshots gets more expensive when there are many snapshots due to backref search and metadata updates. I have no idea how it compares to overlayfs. But then also some use cases I guess it's non-trivial benefit to leverage a shared page cache. > Btrfs + overlayfs? The copy-up coperation in overlayfs can take > advantage of btrfs's clone, but this benefit applies for xfs, too. Btrfs supports fs shrink, and also multiple device add/remove so it's pretty nice for managing its storage in the cloud. And also seed device might have uses. Some of it is doable with LVM but it's much simpler, faster and safer with Btrfs. And that's why I'm kinda curious about the combination of Btrfs and overlayfs. Overlayfs managed by Docker. And Btrfs for simpler and more flexible storage management. -- 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
