On Dec 28, 2013, at 1:34 PM, Richard Michael <rmichael@xxxxxxxxxxxxxxxx> wrote: > > Is the journal on the received side useless? In my case, I'm unable to reproduce the problem. I get the same sha256sum of an existing 16M journal file (in the read only snapshot) as I do in the send/received snapshot. The difference is the original is compromised of 1976 extents, while the received is in a single extent. This is kernel 3.12.5-301.fc20 and btrfs-progs 3.12. I am slightly bugged about a 16MB file having nearly 2000 extents, basically it's being turned into a bunch of 8KB fragments. I know nothing of the pros and cons of how systemd is writing journals, but they don't seem very big so I don't understand why they're preallocated, which on btrfs appears instantly defeated by COW upon the journal being modified. It seems to me either the journal doesn't need to be preallocated (at least on btrfs) or maybe systemd should set xattr +C on /var/log/journal? That does disable checksumming though, along with data cow. 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
