Comment 5 for bug 1948995

You can set the number of revisions to keep with `snap set system refresh.retain=<n>`. The choice for Server is probably unfortunately a victim of inheriting the default choice for Ubuntu Desktop, which is 2. We originally had 3 for Desktop too (which is also still the default on Ubuntu Core), but that was deemed to be too storage intensive for most users so for "non-Ubuntu Core" we changed it to 2 instead, and it seems that Server has gotten bundled into the definition of "non-Ubuntu Core". I think there's a strong case to be made for having a different default on Server vs Desktop, so if you want to open a new bug about changing that (or we could re-use this one I suppose), I think that's a reasonable thing to request be changed.