On Wed, Oct 31, 2012 at 2:18 PM, Gandalf Corvotempesta <[email protected]> wrote: > In a multi replica cluster (for example, replica = 3) is safe to set > journal on a tmpfs? > As fa as I understood with journal enabled all writes are wrote on > journal and then to disk in a second time. > If node hangs when datas are still on journal (and journal is not on a > permanent disk), some data lost could happens. > > In a multi replica environment, other nodes should be able to write > the same datas to disk, right? I this case, using a journal on a tmpfs > should be safe enough.
Unless you're using btrfs which writes to the journal and osd fs concurrently, if you lose the journal device (such as due to a reboot), you've lost the osd device, requiring it to be remade and re-added. This is what I understand at least. If I'm wrong one of the devs will strike me down I'm sure ;) t. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
