Re: [PATCH manager] fix #8193: ceph: pool set: keep min_size when changing size

[Kefu Chai <k.chai@proxmox.com>]

On Sun Oct 18, 2026 at 10:52 PM CEST, Parker Wahle wrote:
[snip]
> @@ -304,6 +304,8 @@ sub set_pool {
>              print "$err";
>          } else {
>              delete $param->{$setting};
> +            # Ceph resets min_size when size changes, so re-read before comparing the rest
> +            $current_properties = get_pool_properties($pool, $rados) if $setting eq 'size';
>          }
>      }

Thanks for tracking this down! I could reproduce it on a three-node
lab cluster running Ceph 21.1.2, with osd_pool_default_min_size = 2.
Without the patch, both of your examples lose the requested min_size:

- a 2/1 pool set to size=3 min_size=1 ends up with min_size 2
- a 4/3 pool set to size=3 min_size=3 ends up with min_size 2

With the patch, both keep the min_size that was asked for. I also
tried changing only the size, which still gives Ceph's default
min_size, and changing only min_size, which works as before. The pool
is only re-read when the size actually changes, which seems fine to
me.

Tested-by: Kefu Chai <k.chai@proxmox.com>
Reviewed-by: Kefu Chai <k.chai@proxmox.com>