Subject: Re: Vinum (was: Volume managers (was Re: someone mentioned "the 1.5 branch"...))
To: None <current-users@netbsd.org>
From: Paul Newhouse <newhouse@totalarchive.com>
List: current-users
Date: 07/03/2000 01:37:01
On Tue, 27 Jun 2000 22:04:33 -0400 (EDT) Jim Wise <jwise@draga.com> wrote:

>In principle I'm aware of the difference between RAID systems and LVM's,
>having used SGI's, Sun's (really Veritas'), and to some extent IBM's LV
>systems, but I had been under the impression that one of the key
>features of an LVM is integration with the file system it is used with
>-- for example the resizable live filesystem capability on AIX is more a
>feature of IBM's JFS, and SGI's logical volume system is inextricably
>linked with the non-LVM features of its XFS implementation.  It is my
>impression from the USENIX paper last year that Vinum is not integrated
>with any file system, though I may be confused...

You are just talking about some middleware foo.  You provide the correctly named
function that maps the grow/shrink  (whatever it's called) syntax to the
correct volume manager actions.  The XFS interface was different than that of 
Sun, HP (well, HP doesn't have much of an extended interface ... I don't think 
it has any actually) or VxFS but, the interface wasn't difficult to map to VxVM.

>So, I guess what I'm not sure of in your answer is:  What features of
>Vinum, not present in RF, make it an LVM as opposed to a RAID system?

I just started looking at Vinum and know nothing of RF.  A comparision list could
be useful if we avoid the flame war pothole.

Paul