On Tue, Nov 19, 2019 at 01:18:21PM +0800, Alberto Bursi wrote: > >> Thanks. This is going to change the behaviour with a missing device, so > >> the question is if we should make this configurable first and then > >> switch the default. > > Configurable then switch makes sense for most cases, but for this > > degraded chunk case, IIRC the new behavior is superior in all cases. > > > > For 2 devices RAID1 with one missing device (the main concern), old > > behavior will create SINGLE/DUP chunk, which has no tolerance for extra > > missing devices. > > > > The new behavior will create degraded RAID1, which still lacks tolerance > > for extra missing devices. > > > > The difference is, for degraded chunk, if we have the device back, and > > do proper scrub, then we're completely back to proper RAID1. > > No need to do extra balance/convert, only scrub is needed. > > > > So the new behavior is kinda of a super set of old behavior, using the > > new behavior by default should not cause extra concern. > > I think most users will see this as a bug fix, as the current behavior > of creating > > SINGLE chunks is very annoying and can cause confusion as it is NOT an > > expected behavior for a classic (mdadm or hardware) degraded RAID array. Thanks for the feedback, I agree with that. It's good to have a confirmation from somebody outside of developer group.
