[dm-devel] [RFC] multipath userspace support

[christophe varoqui]

KC :
> I'm not entirely sure what you mean...but I'm also not very familiar with 
> multipath hardware and associated terminology. What does "cloning and 
> snaping" mean?
> 
this terms apply to storage arrays that embed a volume manager. Thus :

* Snaps are the equivalent of DM snapshots
* Clones are snapshots volumes with background copying

These two features will clone the on-plater UID, which leads to bad 
paths coalescing if based on this UID

> I'm also not personally keen on identifying multipath devices through on-disk 
> metadata. But some people seem to want to use it.
 >
may be it is just a matter of education :)

> I was always pretty happy 
> with the SCSI-midlayer approach that guys like Mike Anderson, Pat Mansfield 
> and Mike Christie were working on, but the powers-that-be decided that wasn't 
> the way to go.
> 
Given the number of policies I already implemented in this early stage 
tools, I can't really say these powers-that-be were wrong :)

regards,
cvaroqui