Re: [PATCH v2 storage,cluster,manager 0/13] multipath: cluster-wide config, storage and health overview

[Dominik Csapak <d.csapak@proxmox.com>]

had a look over the code (a bit) and that looked fine
(see the nits/comments on the individual patches).

but wanted to give a bit more high level feedback (mostly UI) here:

as dietmar already mentioned this kind of interface could be confusing
when we have NVMEoF support as that normally does not use multipath

also the split view of multipath (datacenter/node) is a pattern
we don't often use (we do for e.g. ZFS replication/ceph though)
and it has some limitations (not seeing every detail in the
cluster overview) that could be overcome with a different approach:

we could (similarly to how the pci mapping does it) have a
global grid/tree/etc. that loads the status from the individual nodes
via the api, and injects that status in the grid/tree

that way we could still have full details in a global overview,
and probably would not need the kv cache for the cluster at all
(except if we want to keep that for api consumers, which
would be understandable)

this is a pattern i'd like to use a bit more, since it gives
us the possibility to
* reuse the node local api calls
* have a 'cheap' global view that still shows details
* does not prevent us to still show a node local variant

if we don't want to do something like this, a short link
from the global to local view would be good at least.

Other than that, I'd find it better if one would not have to look
up the wwid themselves, but if we had a view of 'remote disks'
(e.g. fc, iscsi, nvme-o-f) somewhere that we could 'add into'
multipath. With that we could even warn/forbid adding nvme
disks to it at all.

(I'd filter out true local disks, if we can detect that...)

Also, I mentioned it in the patch specific feedback but i wanted
to highlight it here:

having a dynamic number of columns doesn't strike me as a
very good pattern, especially if there can be many, so having
the nodes as columns feels wrong to me...

what do you think?