On May 19, 2013, at 12:18 PM, Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote: > > It's not possible to mount regular directories with other file systems. In some ways the btrfs subvolume behaves like a folder. In other ways it acts like a device. If you stat the mount point for btrfs subvolumes, you get a unique device ID for each. Also a possible use case for btrfs subvolumes as virtual devices, if this isn't already possible or reliable, is in place of LV's for virtual machines. It's very convenient to point a VM to local LVM storage, and have it use an LV which can easily be created, located, and destroyed, and presented to the VM as a single block device. A btrfs subvolume isn't a block device of course, but if it can be pointed to in this fashion it would make it as useful in this scenario as LVs. Otherwise I have to create another btrfs file system on a qcow2 image which then resides on btrfs. So it's double btrfs which performance wise I think is an undesirable hit. 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
