I am not Kent.. but I can answer your questions. 8<--- snip ---->8 > A question for Kent, once you have bcache and it's tools built, > installed and running, is there anything to stop a user from always > tagging devices of whatever type you choose from having the superblock > info to accept a cache dynamically? Example, if I create an MD RAID > device and before I pvcreate or anything else with it I prep it for > bcache but don't actually attach a cache device, is there any negative > effects that can come from that? Can I then at anytime attach a cache > device to it? I realize that once attached in writeback it becomes > non-detachable. Same question for raw sd devices and LVM volumes. In short yes, there are no detrimental effects for having backing devices with superblocks that don't have associated cache sets. To touch on the second point about writeback - it's not so much that it's non-detachable it's that you don't want the backing device to be used while the cache is not attached and is dirty (contains unflushed data). You can detach the cache safely from a writeback device by first switching the cache to writethrough (or none from memory) and waiting for the data to flush to the backing device. Once that is done you can either continue to use it in writethrough mode or you can detach it completely. -- CTO | Orion Virtualisation Solutions | www.orionvm.com.au Phone: 1300 56 99 52 | Mobile: 0428 754 846 -- 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
