On 08/02/2017 08:47 PM, Chris Mason wrote: >> I agree, MD pretty much needs a separate device simply because they can't allocate arbitrary space on the other array members. BTRFS can do that though, and I would actually think that that would be _easier_ to implement than having a separate device. >> >> That said, I do think that it would need to be a separate chunk type, because things could get really complicated if the metadata is itself using a parity raid profile. > > Thanks for running with this Liu, I'm reading through all the patches. I do agree that it's better to put the logging into a dedicated chunk type, that way we can have it default to either double or triple mirroring. Sorry for reply a bit late :-), however it should be sufficient to start the writes from the stripe boundary. For a filesystem this is complicate to grant, however for a journal it would be more simple to do; BR G.Baroncelli -- gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 -- 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
