Rich Freeman <ri...@gentoo.org> wrote:
>>
>> For containers, at least a dozens of binds are minimally required
>> (/usr /proc /sys /dev ...).
>
> I wouldn't be surprised if it works with a single bind mount with
> /proc and /dev and so on mounted on top of that.
Either you start with a writable tree and bind-mount some directories
non-writable or the opposite way. Either way, a dozen or so bind-mounts
are minimally necessary.
> You say "not even a bind" as if that is a benefit.
In case the "non-scaling" argument has not become clear,
I try to visualize it by a table:
| "simple" | "fine grained"
---------+----------------+-------------------
Overlay | 1 mount | 1 mount
---------+----------------+-------------------
Container| 10? bind mounts| 1000? bind mounts
> Honestly, you can't really claim that overlayfs is superior to bind
Correct. If the number of bind mounts really has no influence on the
file operations in the corresponding part of the tree - e.g. if there
is really a clever hashing of bind mounts - the above table does not
indicate any scaling problem.
We are at a point where some kernel source code inspection (or at the
very least serious benchmarking, preferrably with a slow and low-memory
machine) is needed before we can continue the discussion in a serious
way. I do not have the time for this currently.
