From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i810iO316924 for ; Tue, 31 Aug 2004 20:44:24 -0400 Received: from cmss-mail.Tickets.com (cmss-mail.tickets.com [207.213.219.4]) by mx3.redhat.com (8.12.11/8.12.10) with ESMTP id i810iHWT023466 for ; Tue, 31 Aug 2004 20:44:18 -0400 Message-ID: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> From: "Yang, Daniel" Date: Tue, 31 Aug 2004 17:44:04 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C48FBC.C834E5B0" Subject: [linux-lvm] LVM2 and Software RAID Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: To: linux-lvm@redhat.com This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C48FBC.C834E5B0 Content-Type: text/plain What information can you give on the reliability of using LVM2 w/ Software RAID? I've done some reading that stated that LVM and Software RAID on Linux is not a good combination. Especially b/c the combination does not allow for adding or removing hard drives. Also, LVM does not allow for mirroring capabilities so there is no way to mirror w/o the software RAID. Finally, the combination does not support bad-block replacement mechanisms. What can one do if a bad-block occurs in this type of setup? Thanks, DY ------_=_NextPart_001_01C48FBC.C834E5B0 Content-Type: text/html Content-Transfer-Encoding: quoted-printable

What information can you give on the reliability of = using LVM2 w/ Software RAID? I’ve done some reading that stated = that LVM and Software RAID on Linux is not a good combination. Especially = b/c the combination does not allow for adding or removing hard drives. Also, = LVM does not allow for mirroring capabilities so there is no way to mirror w/o = the software RAID. Finally, the combination does not support = bad-block replacement mechanisms. What can one do if a bad-block occurs in = this type of setup?

Thanks,

------_=_NextPart_001_01C48FBC.C834E5B0-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i81FJW320950 for ; Wed, 1 Sep 2004 11:19:32 -0400 Received: from bluebottle-fe2.bluebottle.com (bluebottle-fe2.bluebottle.com [209.223.237.199]) by mx1.redhat.com (8.12.10/8.12.10) with ESMTP id i81FJUS0028939 for ; Wed, 1 Sep 2004 11:19:31 -0400 Received: from localhost.localdomain (modem-4031.chimpanzee.dialup.pol.co.uk [217.134.127.191]) (authenticated bits=0) by bluebottle-fe2.bluebottle.com (8.12.11/8.12.11) with ESMTP id i81FJPv9032067 for ; Wed, 1 Sep 2004 10:19:27 -0500 Date: Wed, 1 Sep 2004 16:22:34 +0100 From: Robin Green Subject: Re: [linux-lvm] LVM2 and Software RAID Message-ID: <20040901152234.GB4300@localhost.localdomain> References: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="v9Ux+11Zm5mwPlX6" Content-Disposition: inline In-Reply-To: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: To: LVM general discussion and development --v9Ux+11Zm5mwPlX6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Aug 31, 2004 at 05:44:04PM -0700, Yang, Daniel wrote: > Finally, the combination does not support bad-block replacement mechanism= s. Bad block replacement has been implemented in hardware for years so this is not an issue. If you get a huge number of bad blocks you should really consider replacing the drive concerned. --=20 Robin Weblog: http://lrp.greenrd.org/ --v9Ux+11Zm5mwPlX6 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQFBNek6tPCt67UksSYRAmj8AKDQy+5HDw/YhFdf+9Zb2AnWNfNy+QCg2FsQ 1Z+NS6mHLNB3YGr3zDod1v4= =7N6u -----END PGP SIGNATURE----- --v9Ux+11Zm5mwPlX6-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i81Htp307325 for ; Wed, 1 Sep 2004 13:55:51 -0400 Received: from ripple.fruitbat.org (ip-66-80-62-153.dsl.sca.megapath.net [66.80.62.153]) by mx1.redhat.com (8.12.10/8.12.10) with ESMTP id i81HtnS0010400 for ; Wed, 1 Sep 2004 13:55:50 -0400 Received: (from daemon@localhost) by ripple.fruitbat.org (8.10.2/8.8.8/PAC-1.3) id i81HsOk24687 for ; Wed, 1 Sep 2004 10:54:24 -0700 Received: from ming.fruitbat.org (IDENT:202@ming.fruitbat.org [192.168.1.2]) by ming.fruitbat.org (8.12.10/8.10.2/PAC-1.6) with ESMTP id i81HsDE8010753 for ; Wed, 1 Sep 2004 10:54:13 -0700 Date: Wed, 1 Sep 2004 10:54:13 -0700 (PDT) From: "Peter A. Castro" Subject: Re: [linux-lvm] LVM2 and Software RAID In-Reply-To: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> Message-ID: References: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> MIME-Version: 1.0 Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: TEXT/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LVM general discussion and development On Tue, 31 Aug 2004, Yang, Daniel wrote: > What information can you give on the reliability of using LVM2 w/ Software > RAID? I've done some reading that stated that LVM and Software RAID on > Linux is not a good combination. Especially b/c the combination does not > allow for adding or removing hard drives. Also, LVM does not allow for > mirroring capabilities so there is no way to mirror w/o the software RAID. > Finally, the combination does not support bad-block replacement mechanisms. > What can one do if a bad-block occurs in this type of setup? There are always pros and cons for using RAID and LVM. For my money, software raid is more flexible and more managable than hardware raid. Others may disagree, of course :) RAID is mostly about planning how you want your disks to be spliced together and what kind of reliability over failure you are willing to live with. This is true for software and hardware RAID. Most hardware RAID adapters do not allow for resizing an existing array. It is possible to resize a software RAID, but there is the potential for data loss. The Software-RAID HOWTO has a quick section on RAID resizing which might interested you. See: http://tldp.org/HOWTO/Software-RAID-HOWTO.html Software RAID, as you are aware, uses the computers processor to perform the raid functions, where as hardware RAID has a separate processor on the RAID adapter to perform these functions. If you have a sufficiently fast computer, the overhead of raid will hardly be noticed. LVM, by contrast, is geared for adding and removing physical drives from a volume group allowing one to add more storage or replace smaller drives with larger ones. The problem most people have is that they create one big raid array and thus have only one volume group with only one physical device in it. Kinda hard to remove a device and retain your data in this configuration :) Most modern drives have automatic bad-block replacement internally. If the drive has more bad-blocks than available replacement blocks, then likely the drive is header for failure anyways and should be replaced. Perhaps you should consider what you want to do with your arrays. If you expect to be needing to add more redundant storage over time, then perhaps a solution would be to create several small raid arrays on several drives. Each array appears as a single "drive" to the system. This way, you can group several "drives" together in a volume group. If you need to add storage, you simple replace one arrays' set of drives. With LVM, you can move data off of that "drive", remove it from the volume group, change out the physical drives, create the new array on these drives, then add it back into the volume group, or simply add new disks, create a new array and add it to the volume group. Again, it's all about planning. With Software RAID and LVM you have more flexibility, and the above can be done while the system is live. Most hardware raids have to be setup from the adapters bios. Good luck, whichever you choose. > Thanks, > DY -- Peter A. Castro or "Cats are just autistic Dogs" -- Dr. Tony Attwood From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i81I0x309117 for ; Wed, 1 Sep 2004 14:00:59 -0400 Received: from stl.rural.usda.gov (stl.rural.usda.gov [199.159.138.244]) by mx3.redhat.com (8.12.11/8.12.10) with ESMTP id i81I0qAk029979 for ; Wed, 1 Sep 2004 14:00:52 -0400 Received: from [192.168.123.4] (monkey.rural.usda.gov [199.159.140.179]) by stl.rural.usda.gov (8.12.11/8.12.10) with ESMTP id i81Hv10o010936 for ; Wed, 1 Sep 2004 12:57:02 -0500 Message-ID: <41360E48.3030709@charter.net> Date: Wed, 01 Sep 2004 13:00:40 -0500 From: James P MIME-Version: 1.0 References: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> <20040901152234.GB4300@localhost.localdomain> In-Reply-To: <20040901152234.GB4300@localhost.localdomain> Content-Transfer-Encoding: 7bit Subject: [linux-lvm] LVM and Ghost Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: LVM general discussion and development Some of our admins are running into trouble running Norton Ghost on our RHEL ES 3.0 boxes. Ghost claims it doesn't recognize what's on the disk so it just does a raw dump of the entire (36 Gig) disk. This offers practically zero compression, so we're getting ghost images that are many times larger than the amount of actual used space on the machine. The only difference I can think of between these machines and our other Linux boxes that ghost perfectly well is that these are using LVM. Is this causing the problem with Ghost? Has anyone else run into this? What can we do to get Ghost to recognize where the data is on the disk so we can get some sort of reasonably sized images? Anything? --James From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i81ILS316157 for ; Wed, 1 Sep 2004 14:21:28 -0400 Received: from percy.comedia.it (percy.comedia.it [212.97.59.71]) by mx1.redhat.com (8.12.10/8.12.10) with ESMTP id i81ILLS0018562 for ; Wed, 1 Sep 2004 14:21:27 -0400 Date: Wed, 1 Sep 2004 20:21:20 +0200 From: Luca Berra Subject: Re: [linux-lvm] LVM and Ghost Message-ID: <20040901182120.GF7576@percy.comedia.it> References: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> <20040901152234.GB4300@localhost.localdomain> <41360E48.3030709@charter.net> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <41360E48.3030709@charter.net> Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" Content-Transfer-Encoding: 7bit To: LVM general discussion and development do not hijack other people threads, that said, probably norton ghost does not understand lvm. you could look at Mondo Rescue (http://www.mondorescue.org/) L. On Wed, Sep 01, 2004 at 01:00:40PM -0500, James P wrote: >The only difference I can think of between these machines and our >other Linux boxes that ghost perfectly well is that these are using >LVM. Is this causing the problem with Ghost? Has anyone else run L. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \ From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i81IPI317168 for ; Wed, 1 Sep 2004 14:25:18 -0400 Received: from email.careercast.com (email.careercast.com [216.39.101.233]) by mx1.redhat.com (8.12.10/8.12.10) with SMTP id i81IPCS0019496 for ; Wed, 1 Sep 2004 14:25:18 -0400 Subject: Re: [linux-lvm] LVM and Ghost From: Clint Byrum In-Reply-To: <41360E48.3030709@charter.net> References: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> <20040901152234.GB4300@localhost.localdomain> <41360E48.3030709@charter.net> Message-Id: <1094063096.12875.46.camel@localhost> Mime-Version: 1.0 Date: Wed, 01 Sep 2004 11:24:56 -0700 Content-Transfer-Encoding: 7bit Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development On Wed, 2004-09-01 at 11:00, James P wrote: > Some of our admins are running into trouble running Norton Ghost on > our RHEL ES 3.0 boxes. Ghost claims it doesn't recognize what's on > the disk so it just does a raw dump of the entire (36 Gig) disk. > This offers practically zero compression, so we're getting ghost > images that are many times larger than the amount of actual used > space on the machine. > > The only difference I can think of between these machines and our > other Linux boxes that ghost perfectly well is that these are using > LVM. Is this causing the problem with Ghost? Has anyone else run > into this? What can we do to get Ghost to recognize where the data > is on the disk so we can get some sort of reasonably sized images? > Anything? > Yes this is a Ghost problem. Ghost has no idea what LVM is. To it, LVM appears as an unknown filesystem. You'll have to ask symantec to add LVM support. Just curious.. why even use ghost with RH Linux servers? I suppose multicasting everything is nice.. but a two step process where you use a kickstart for the install, and then a multicast file copy program (like mcp, http://www.cl.cam.ac.uk/users/kj234/mcp/) for any data would at least let you use free tools to accomplish your goal, and not leave you hanging when you switch filesystems. ;) From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i81IWn319723 for ; Wed, 1 Sep 2004 14:32:49 -0400 Received: from storix.com ([206.71.178.18]) by mx1.redhat.com (8.12.10/8.12.10) with ESMTP id i81IWmS0021511 for ; Wed, 1 Sep 2004 14:32:49 -0400 Received: from [192.168.1.126] (65.106.88.139.ptr.us.xo.net [65.106.88.139]) by storix.com (Postfix) with ESMTP id A171315832 for ; Wed, 1 Sep 2004 11:24:55 -0700 (PDT) Subject: Re: [linux-lvm] LVM and Ghost From: rich turner In-Reply-To: <20040901182120.GF7576@percy.comedia.it> References: <63BAEF7DCB973A469B1A60CBE113C1650872A631@cmss-mail.Tickets.com> <20040901152234.GB4300@localhost.localdomain> <41360E48.3030709@charter.net> <20040901182120.GF7576@percy.comedia.it> Message-Id: <1094063612.3399.44.camel@rich> Mime-Version: 1.0 Date: Wed, 01 Sep 2004 11:33:33 -0700 Content-Transfer-Encoding: 7bit Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development or you could look at Storix which definitely supports LVM. On Wed, 2004-09-01 at 11:21, Luca Berra wrote: > do not hijack other people threads, > that said, probably norton ghost does not understand lvm. > you could look at Mondo Rescue (http://www.mondorescue.org/) > > L. > On Wed, Sep 01, 2004 at 01:00:40PM -0500, James P wrote: > >The only difference I can think of between these machines and our > >other Linux boxes that ghost perfectly well is that these are using > >LVM. Is this causing the problem with Ghost? Has anyone else run > > L.