From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [linux-lvm] software RAID over LVM From: Austin Gonyou In-Reply-To: <3C5831E7.9060705@birddog.com> References: <3C5831E7.9060705@birddog.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-qAoCXkDfHO1c6P+ih+JM" Message-Id: <1012413308.12412.3.camel@UberGeek> MIME-Version: 1.0 Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: Date: Wed Jan 30 11:55:04 2002 List-Id: To: linux-lvm@sistina.com --=-qAoCXkDfHO1c6P+ih+JM Content-Type: text/plain Content-Transfer-Encoding: quoted-printable I was stating that it's the way you'd want to do that. Doing otherwise would be bad. :)=20 On Wed, 2002-01-30 at 11:48, Kirby C. Bohling wrote: > Austin, >=20 > Just as an aside, I have done all of those configurations with > no LVM=20 > involved. RAID0+1, RAID1+0, and RAID5 on top of mirrored devices. Yes=20 > RAID1+0 isn't very smart, but we did it. It is much simpiler, and more=20 > reliable to have RAID underneath LVM. Not because LVM is unreliable,=20 > but if you forget, or don't realize both halves of a mirror got migrated >=20 > to the same disks your mirror might be a lot less redundant then you=20 > believe it is. Wow, I just restated the a FAQ entry in a very poor=20 > manner... >=20 > LVM didn't try to be all incompassing. It could have been, but > it would=20 > have made things more complicated and duplicated a bunch of work from=20 > what I have read on this list. >=20 > Kirby >=20 >=20 > 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. > >=20 > >=20 > > On Tue, 2002-01-29 at 17:50, Kirby C. Bohling wrote: > >=20 > >>Paul, > >> > >> I haven't done it. I have done mirrors underneath, but I am > >>curious what=20 > >>is the reasoning and/or application. The only thing I can think up is >=20 > >>so you can migrate your mirrors to faster drives easily. However,=20 > >>putting the mirror underneath should allow you to move off one mirror=20 > >>onto another. > >> > >> I don't believe that mirroring can be expanded like a filesystem > >>can. In=20 > >>order to make the mirror bigger, you have to break the mirror as far > as=20 > >>I know. So what are you planning on doing with it, or is it just "to=20 > >>see if it could be done". > >> > >> Thanks, > >> Kirby > >> > >>lvm@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@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@sistina.com > >>http://lists.sistina.com/mailman/listinfo/linux-lvm > >>read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html > >> >=20 >=20 >=20 > _______________________________________________ > linux-lvm mailing list > linux-lvm@sistina.com > http://lists.sistina.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html --=20 Austin Gonyou Systems Architect, CCNA Coremetrics, Inc. Phone: 512-698-7250 email: austin@coremetrics.com "It is the part of a good shepherd to shear his flock, not to skin it." Latin Proverb --=-qAoCXkDfHO1c6P+ih+JM Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQA8WDN894g6ZVmFMoIRAp+pAKDJFpH1V9u2RolMXuEtICdihE78IACcDoEk Mz9nCV+svrv13/qwWCzJPFA= =8Pil -----END PGP SIGNATURE----- --=-qAoCXkDfHO1c6P+ih+JM--