Re: [linux-lvm] pvcreate problem

["Heinz J . Mauelshagen" <mauelshagen@sistina.com>]

On Fri, Dec 06, 2002 at 09:26:24AM -0600, Alexander Lazarevich wrote:
> hmm, thanks heinz. ive got it setup now with all the lvm volumes on
> /dev/sdb. fdisk sees no partitions. based off what you said, im wondering
> if i should remove all the lvm volumes, do an fdisk of /dev//sdb and
> create a single partition on the whole disk, and then redo the lvm stuff.
> 
> should i really do that? or is it not that big a deal? any performance
> difference? or is it just that fidks and other tools won't see any
> partitions on the device?

It is just the danger to overlook that the disk is in use because tools
and proc entries don't show.

So if you keep track and remember that you use the whole device you can
just keep it the way it is.

> 
> thanks for the advice!

You're welcome :)

Regards,
Heinz    -- The LVM Guy --

> 
> alex
> ---                                                        ---
>    Alex Lazarevich | Systems | Imaging Technology Group
>    alazarev@itg.uiuc.edu | (217)244-1565 | www.itg.uiuc.edu
> ---                                                        ---
> 
> 
> On Fri, 6 Dec 2002, Heinz J . Mauelshagen wrote:
> 
> > On Thu, Dec 05, 2002 at 05:27:01PM -0600, Alexander Lazarevich wrote:
> > > i just installed a fresh RH linux 7.3, with LVM 1, or whatever comes in
> > > the RH distribution.
> > >
> > > ihe first thing i'm trying to do is pvcreate on my big RAID 5 array, which
> > > is /dev/sdb:
> > >
> > > [root@discord root]# pvcreate /dev/sdb
> > > pvcreate -- ERROR: can't initialize physical volume "/dev/sdb" of volume
> > > group "homevg" without -ff
> > >
> > > but there is no volume group homevg:
> > >
> > > [root@discord root]# vgdisplay homevg
> > > vgdisplay -- volume group "homevg" not found
> > >
> > > i am able to fdisk a partition onto /dev/sdb, and then do a pvcreate on
> > > that partition, but i want to do a pvcreate on the whole free volume, no
> > > partitions! i may have made a typo before, by trying to do a pvcreate
> > > /dev/sdb, i instead did a vgcreate /dev/sdb. and them i might have tried
> > > some other crap cause it was freeking out. i rebooted so i can see the
> > > history, unless lvm keeps some kind of log file? i couldnt find one.
> >
> > No log file ITR.
> > In general having at least one partition per device is a good idea, because
> > sources like /proc/partitions or tools like fdisk find that there's something
> > on the device. You loose _very_ little capacity that way.
> >
> > If you still want to use /dev/sdv directly "pvcreate -ff /dev/sdb;vgcreate ..."
> > should do it after you remove any partition table from /dev/sdb again.
> > Eventually you need a "dd if=/dev/zero of=/dev/sdb bs=512 count=1" _after_
> > you removed the partition table.
> >
> > >
> > > i rebooted, etc. id prefer not to have to reinstall everything. how do i
> > > fix this problem?
> > >
> > > any ideas?
> > >
> > > thanks in advance!
> > >
> > > alex
> > > ---                                                        ---
> > >    Alex Lazarevich | Systems | Imaging Technology Group
> > >    alazarev@itg.uiuc.edu | (217)244-1565 | www.itg.uiuc.edu
> > > ---                                                        ---
> > >
> > >
> > >
> > > _______________________________________________
> > > linux-lvm mailing list
> > > linux-lvm@sistina.com
> > > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> >
> > --
> >
> > Regards,
> > Heinz    -- The LVM Guy --
> >
> > *** Software bugs are stupid.
> >     Nevertheless it needs not so stupid people to solve them ***
> >
> > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> >
> > Heinz Mauelshagen                                 Sistina Software Inc.
> > Senior Consultant/Developer                       Am Sonnenhang 11
> >                                                   56242 Marienrachdorf
> >                                                   Germany
> > Mauelshagen@Sistina.com                           +49 2626 141200
> >                                                        FAX 924446
> > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> >
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> >
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

-- 

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

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Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@Sistina.com                           +49 2626 141200
                                                       FAX 924446
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