Re: [libvirt] [PATCH v3 4/4] logical: Display thin lv's found in a libvirt managed volume group

On 02/03/2016 03:23 AM, Ján Tomko wrote: > On Tue, Feb 02, 2016 at 11:14:01AM -0500, John Ferlan wrote: >> >> >> On 02/02/2016 08:30 AM, Pavel Hrdina wrote: >>> On Tue, Feb 02, 2016 at 09:11:51AM +0100, Ján Tomko wrote: >>>> A thin pool is another layer on top of some of the LVs in the VG. >>>> I think it deserves a separate pool type. >>> >>> I must agree with Jan, and also already wrote the same for v2 patch. The thin >>> pool and thin LV shouldn't be mixed with normal logical pool even they share the >>> same VG. >>> >> >> If LVM allows it, then who are we to say it cannot or shouldn't work or >> how it should be configured? > > Even if they are mixed in the same VG, we could show the "thick" LVs > in the type='logical' pool and the thin ones in type='thin'. > We could if our logic to create/build the pool was overhauled or perhaps support was added to have two volume groups use the same source device. Since it's possible to place a thin_pool in the same vg as a snapshot and a "thick" lv, should we be in the business of splitting hairs and trying to define how things should be viewed?

I don't see the benefit behind requiring the user to decide whether to have a libvirt pool view either thin lv's or non-thin lv's of their vg or requiring their vg to essentially be one thin-pool in order to support thin lv's, when we could support whatever configuration they've already developed.

If more work is done in LV pools - are we going to create new pool types for other lvm segtypes ("mirror", "stripe", "raid", etc.)? In order to display/fetch interesting or specific things about them?