On Fri, May 24, 2019 at 3:51 AM Michal Soltys <soltys@xxxxxxxx> wrote: > > On 5/23/19 8:09 PM, Song Liu wrote: > >>> > >> > >> Actually, this seems to be unreleated to underlying devices - the culprit seems to be attempting to write to an array after adding journal, without stopping and reassembling it first. Details below. > > > > Thanks for these experiments. Your analysis makes perfect sense. > > > > Do you think you can continue the experiments with the write journal before > > this issue got fixed? > > > > I am asking because this is not on the top of my list at this time. If > > this is not > > blocking other important tests, I would prefer to fix it at a later time. > > > > Thanks, > > Song > > > > Yea it's fine. I can help with testing (whenever you sit down to this > issues) as well. > > Question though - other than trying to add journal to existing live raid > - is this feature overall safe to use (or are there any other know > issues one should be aware of beforehand) ? > We (Facebook) have done some tests with it. However, we didn't put it into production. The reason behind this decision was not reliability, but performance concerns and high level directions. I think Redhat is evaluating it. + Xiao, who might be working on this. Thanks, Song
