Re: [linux-lvm] need help to recover my system

[Les Hazelton <seawolf@attglobal.net>]

My kernel had LVM support compiled in, not as a module.  I had created an initrd but
may have not done that correctly.  I think the real problem was that the grub loader
was installed on the root "/" partition and not the "/boot" partition.  I had booted
the new configuration several times without problem until I deleted the original "/"
partition.  That's when I realized where the grub loader was installed.

When I use linux fdisk I see the entry for hdc5 as Linux LVM (85) and if I do "cat
/proc/partitions"  there is an entry for /dev/hdc5.

If, while running my test system with kernel 2.4.0, I run the pvcreate command for
/dev/hdc5 will that destroy the existing PV, VG, LVM content that is currently their?

"Heinz J. Mauelshagen" wrote:

> On Sat, Sep 30, 2000 at 11:02:36PM -0400, Les Hazelton wrote:
> > I had a Mandrake 7.1 system running the 2.2.17 kernel with LVM and
> > reiserfs patches applied.  I have a 15Gb partition on /dev/hdc5 which
> > was one large PV. It supports one VG which has the logical volumes for
> > /usr, /home, /var, etc... Everything except /boot and / which were on
> > the hda drive as plain ext2 file systems.
> >
> > I decided to move the root partition "/" to a logical volume on hdc5 and
> > all was going well until I deleted it from the ext2 system on hda6.
>
> How did you do that?
> Did you create an inital ram disk to load the lvm driver and activate
> the volume group?
> Otherwise you can't access your volume group(s) anyway from the /boot
> booted kernel.
>
> > So
> > now I have a perfectly good Linux system contained on the hdc5 PV which
> > I can't access.
> >
> > I have test system (Mandrake 7.2-b) on the hda drive.  It has the
> > 2.4.0-0.22 kernel distributed my Mandrake and I have been attempting to
> > recover using that system.  The problem is I keep getting these errors:
> >
> > ------------------------------------------------------------------------------
> > pvscan -- reading all physical volumes (this may take a while...)
> > pvscan -- ERROR "pv_read_all_pv(): lvm_dir_cache" reading physical
> > volumes
>
> This error means, that no (compatible) entries could be found either
> in /proc/partitions or, if /proc/partitions doesn't exist, in /dev.
>
> Please check that these sources are valid on your Mandrake 7.2-b test system
> and retry.
>
> >
> > [root@farpt1 /root]# vgscan -v
> > vgscan -- removing "/etc/lvmtab" and "/etc/lvmtab.d"
> > vgscan -- reading all physical volumes (this may take a while...)
> > vgscan -- no volume groups found
> > -------------------------------------------------------------------------------
> >
> > I was going to try a pvcreate for /dev/hdc5  but thought it would wipe
> > the partition clean and I don't want to start over if there is *any*
> > hope of recovering it.
> >
> > Please, if anyone knows a way to recover this volume,  I would be
> > extremely grateful for the help.
> >
> > Les Hazelton
>
> --
>
> Regards,
> Heinz      -- The LVM guy --
>
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
>
> Heinz Mauelshagen                                 Sistina Software Inc.
> Senior Consultant/Developer                       Bartningstr. 12
>                                                   64289 Darmstadt
>                                                   Germany
> Mauelshagen@Sistina.com                           +49 6151 7103 86
>                                                        FAX 7103 96
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Les Hazelton