Subject: Re: Something like AIX's Journaled?
To: None <current-users@netbsd.org>
From: DAVID RANKIN <rankind@iglou.com>
List: current-users
Date: 11/19/1998 15:37:23
Gary Duzan said:
> That might get some minimal functionality going, but you still
> would have to use a BSD disklabel on the ccd with all the limitations
> that implies. You're missing a layer of abstraction (or indirection)
> that allows arbitrary placement of partitions on the disk, including
> physically non-contiguous partitions. What you'd want is almost
> like having a bunch of vnode disks configured for files inside a
> file system on a ccd, but not quite. For example, AIX's LVM allows
> you to do things like removing a disk from a volume group, which
> I assume forces any used blocks on that disk to other disks in the
> volume group. I don't think you could get the ccd+vnodes setup to
> do this without serious work.
FreeBSD has Vinum, which is a Veritas-like system pretty close to ccd in
functionality, with the added complexity of "sub-disks". What you really
want is an IBM/HP-like Logical Volume Manager, which AFAIK isn't close yet.
I've been contemplating writing an LVM subsystem which is disk-compatable
(and command-line-compatable where possible) with Heinz Mauelshagen's work
(http://linux.msede.com/lvm/), but I've got so little kernel-driver skill
that I'm barely into the planning stages. Yes, I agree with you: I intend
to have each LV fake a disklabel for a single, whole partition.
If anyone is working on LVM, I know I (and most of the people I know running
BSDs) would love to hear about it.
Thanks,
David
--
David W. Rankin, Jr. Husband, Father, and UNIX System Administrator
Email: rankind@iglou.com Phone Number and Address Upon Request
"Programming is like sex; one mistake and you support it for a
lifetime." -- unknown (to me)