Den tors 21 nov. 2024 kl 09:45 skrev Andre Tann <atann@alphasrv.net>:
Hi Frank, thanks a lot for the hint, and I have read the documentation about this. What is not clear to me is this:
== snip The first category of these failures that we will discuss involves inconsistent networks -- if there is a netsplit (a disconnection between two servers that splits the network into two pieces), Ceph might be unable to mark OSDs down and remove them from the acting PG sets. == snip
Why is Ceph not able to mark OSDs down, and why is it unclear whether or not it is able to do so ("might")?
I think designs with 2 DCs usually have one or two mons per DC, and then a third/fifth mon in a (small) third site so it can arbitrate which side is up and which isn't. OSDs report to each other but also to mons about their existence. -- May the most significant bit of your life be positive.