There are a number of things missing from multiple device support, including any concept of a device becoming faulty (i.e. persistent failures rather than transient which Btrfs seems to handle OK for the most part), and then also getting it to go degraded automatically, and finally hot spare support. There are patches that could use testing.
https://www.spinics.net/lists/linux-btrfs/msg52084.html http://www.spinics.net/lists/linux-btrfs/msg53048.html I think when testing, it's simpler to not use any additional device mapper layers. Yes those should work, but it has to work with Btrfs on the raw partition or device first. Then add additional layers one at a time as the use case requires, testing in between the additions. Otherwise it makes it harder to isolate. Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
