[linux-lvm] lvmlockd: about the limitation on lvresizing the LV active on multiple nodes

[Eric Ren]

Hi David,

>> IIRC, you mean we can consider to use cluster raid1 as the underlaying DM
>> target to support pvmove
>> used in cluster, since currect pvmove is using mirror target now?
> That's what I imagined could be done, but I've not thought about it in
> detail.  IMO pvmove under a shared LV is too complicated and not worth
> doing.

Very true.

>
>> By the way, another thing I'd to ask about:   Do we really want to drop
>> the concept of clvm?
>>
>>  From my understanding, lvmlockd is going to replace only "clvmd" daemon,
>> not clvm in exact.  clvm is apparently short for cluster/cluster-aware
>> LVM, which is intuitive naming. I see clvm as an abstract concept, which
>> is consisted of two pieces: clvmd and cmirrord. IMHO, I'd like to see
>> the clvm concept remains, no matter what we deal with the clvmd and
>> cmirrord. It might be good for user or documentation to digest the
>> change :)
> Thank you for pointing out the artifice in naming here, it has long
> irritated me too.  There is indeed no such thing as "clvm" or "HA LVM",
> and I think we'd be better off to ban these terms completely, at least at
> the technical level.  (Historically, I suspect sales/marketing had a role
> in this mess by wanting to attach a name to something to sell.)
Hha, like cluster MD raid.
>
> If the term "clvm" survives, it will become even worse IMO if we expand it
> to cover cases not using "clvmd".  To me it's all just "lvm", and I don't
> see why we need any other names.
It looks like people need a simple naming to distinguish the usage scenario:
local and cluster.

Thanks,
Eric