Hi, Ricardo I got what you mean. First of all, if we enable the rbd journaling, currently write latency will be doubled since it should wait for finish of the write operation. So If the issue is what you mentioned above. I think we have some other ways to solve it. For example, we can snapshot the primary image and run a whole image scan to find those objects which is different from each other. And then delete the snapshot on the primary and continue to replying journal again. In this way, we can also maintain the image consistency? Regards Ning Yao 2016-08-22 17:31 GMT+08:00 Ricardo Dias <ricardo.dias@xxxxxxxx>: > Hi Jaze, > > If you write data first, and you have a failure after writing data and before writing to the journal, then you cannot recover that write operation and it will be lost. > > You can see the journal as a primary replica of data. > > Ricardo Dias > > Sent from my mobile phone > >> On 22 Aug 2016, at 09:46, Jaze Lee <jazeltq@xxxxxxxxx> wrote: >> >> Hi all: >> I found that rbd journaling first write journal and then write data. >> Why we not first write data and then write journal? Is there some >> considerration >> for which is first ? >> >> Thanks a lot. >> >> -- >> 谦谦君子 >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
