[linux-lvm] software RAID over LVM
Austin Gonyou
austin at coremetrics.com
Wed Jan 30 11:55:04 UTC 2002
I was stating that it's the way you'd want to do that. Doing otherwise
would be bad. :)
On Wed, 2002-01-30 at 11:48, Kirby C. Bohling wrote:
> Austin,
>
> Just as an aside, I have done all of those configurations with
> no LVM
> involved. RAID0+1, RAID1+0, and RAID5 on top of mirrored devices. Yes
> RAID1+0 isn't very smart, but we did it. It is much simpiler, and more
> reliable to have RAID underneath LVM. Not because LVM is unreliable,
> but if you forget, or don't realize both halves of a mirror got migrated
>
> to the same disks your mirror might be a lot less redundant then you
> believe it is. Wow, I just restated the a FAQ entry in a very poor
> manner...
>
> LVM didn't try to be all incompassing. It could have been, but
> it would
> have made things more complicated and duplicated a bunch of work from
> what I have read on this list.
>
> Kirby
>
>
> Austin Gonyou wrote:
> > I can think of MANY uses for this. The main one would be a relatively
> > cheap way of making a RAID0+1, or stripe of mirrors. If you don't have
> > any hardware to do this with, then software is next. It'd be nice to
> be
> > able to do this, for sure. You could even do 0+5, or something crazy
> > like that too.
> >
> >
> > On Tue, 2002-01-29 at 17:50, Kirby C. Bohling wrote:
> >
> >>Paul,
> >>
> >> I haven't done it. I have done mirrors underneath, but I am
> >>curious what
> >>is the reasoning and/or application. The only thing I can think up is
>
> >>so you can migrate your mirrors to faster drives easily. However,
> >>putting the mirror underneath should allow you to move off one mirror
> >>onto another.
> >>
> >> I don't believe that mirroring can be expanded like a filesystem
> >>can. In
> >>order to make the mirror bigger, you have to break the mirror as far
> as
> >>I know. So what are you planning on doing with it, or is it just "to
> >>see if it could be done".
> >>
> >> Thanks,
> >> Kirby
> >>
> >>lvm at agilecat.mailshell.com wrote:
> >>
> >>>Hi all,
> >>>
> >>>I understand the use of LVM over software RAID.
> >>>But is it possible to use software RAID ON TOP
> >>>of LVM? For example, have a RAID-1 mirroring
> >>>array created from two logical volumes.
> >>>
> >>>I've tried and it seems to be working. Is
> >>>it safe to do this? Any pitfalls?
> >>>
> >>>Thanks!
> >>>
> >>>Paul
> >>>
> >>>_______________________________________________________
> >>>The FREE service that prevents junk email http://www.mailshell.com
> >>>
> >>>_______________________________________________
> >>>linux-lvm mailing list
> >>>linux-lvm at sistina.com
> >>>http://lists.sistina.com/mailman/listinfo/linux-lvm
> >>>read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> >>>
> >>>
> >>
> >>
> >>_______________________________________________
> >>linux-lvm mailing list
> >>linux-lvm at sistina.com
> >>http://lists.sistina.com/mailman/listinfo/linux-lvm
> >>read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> >>
>
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
--
Austin Gonyou
Systems Architect, CCNA
Coremetrics, Inc.
Phone: 512-698-7250
email: austin at coremetrics.com
"It is the part of a good shepherd to shear his flock, not to skin it."
Latin Proverb
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 232 bytes
Desc: This is a digitally signed message part
URL: <http://listman.redhat.com/archives/linux-lvm/attachments/20020130/6c452b7c/attachment.sig>
More information about the linux-lvm
mailing list