On 2022-03-17 00:20, Damien Le Moal wrote: >>> But still, zone capacity can vary for each zone. So, we need to read >>> the capacity of a zone where the data BG resides on. >>> >> Do we support variable zone capacity in Linux? IIRC variable zone sizes >> are definitely not supported but I am not sure about variable zone capacity. > > No, variable zone capacity is not supported in Linux. By that, I mean that > drive that may change the capacity of a zone after a reset are not > supported. So a zone capacity in Linux is always fixed throughout the life > time of the NS it belongs to. > > But nothing mandates that all zones have the same capacity. A drive could > expose zones with different capacities. That is the point Naohiro was making. > Got it. Thanks for the clarification. >> >> But even if we do support, I see that the zone 5 (old_data_zone) and >> zone 6 (new_data_zone) during the test and what if the new_data_zone >> (zone 6) has a smaller cap than old_data_zone (zone 5)? >> The main question: Is there a way to deterministically tell where the >> data BG will reside and where it will relocate before we start the test >> with variable capacity? >> @noahiro: So the data BG for btrfs starts from Zone 5 if I understand it correctly. Can I then hard code the test to read the cap from zone 5? I think that should fix your concern. >> My first look indicates that adding variable zone capacity will make the >> test a bit more complex and I am not sure if it is worth the effort if >> there are no use cases for it. >> Let me know your thoughts. >> > > -- Regards, Pankaj
