Re: [Evms] Userspace model and terminology

[Andrew Clausen]

Ben Rafanello wrote:
> As discussed at the last EVMS conference call, one of the problems we have
> in talking about EVMS is terminology.  Several of the terms we were using
> to discuss the EVMS are already in use by other volume management systems
> where they have a different meaning.  This has led to confusion and
> mis-communication.  So at the conference call we decided to try to invent
> an EVMS unique set of terms and definitions.  This has led to much debate
> among the EVMS team members (as well as re-introducing the EVMS team
> members to the Thesaurus - something we all thought we left behind in
> college! ;-) ).

LOL.  BTW: I think it's reasonable to borrow terminology from
elsewhere, so long as that word doesn't have confusing meanings.
You've done this a bit anyway.

> Sector - Standard meaning - lowest level of addressability.  Assumed to be
> on a physical device.

Is this going to be a fixed constant?  512 bytes?

> Logical Disk - The ordered set of contiguous sectors which
> comprise/represent a device.

in Parted: PedDevice.  (BTW: need it be a "physical" device?
Could it be a partition / logical volume, for example?)

> Disk Segment - An ordered set of contiguous sectors residing on a Logical
> Disk.

in Parted: PedGeometry

can we just call it a segment?  It's really nice to have
short names!
 
> Storage Container - A set of one or more Disk Segments.

s/set/ordered set/?  Does it provide a linear address space?

Why not call it a "segment set"?

Also, must the Disk Segments be on the same logical disk?

> Storage Region - An ordered set of logically contiguous sectors residing in
> a Storage Container.

Do you mean, "An ordered set of Disk Segments?".  Actually, how
is this different from a Disk Segment, other than the "Disks"
are "Disk Segments" other than "Logical Disks"?

Perhaps you should call this an "ordered segment set"?

Also, what's the motivation for saying that it's "in a Storage
Container"?

> Storage Object - A logically contiguous address space created from one or
> more Storage Regions or Storage Objects through the use of one or more EVMS
> Features.

It should be abstract / undefined how it is "created".  It should
have an identical interface to a Logical Disk, IHMO.

> Volume - A mountable storage object.

See previous comment.

> Device Manager - responsible for producing Logical Disks.

I think "Disk Manager" is better, if you are going to use
"Logical Disks".
 
Andrew Clausen