Re: [linux-lvm] Problems with vgimport after software raid initialisation failed.

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

Lutz,

looks like you hit some strange LVM on top of MD bug :(

In order to get your VG active again (which of course is your highest
priority) and before we analyze the vgscan problem, you want to go for
the follwoing workaround (presumably /etc/lvmconf/datavg.conf is the last
correct archive of the metadata):

# cp /etc/lvmconf/datavg.conf /etc/lvmtab.d/datavg
# echo -ne "datavg\0" >> /etc/lvmtab
# vgchange -ay datavg

Warning: the next vgscan run will remove the above metadata again, so avoid
         running it for now by commenting it out in your boot script.

So far about firefighting ;)


For further analysis, please do the following and send the resulting
bzip2'ed tar archive containing your metadat to me in private mail
<mge@sistina.com>:

# for d in md2 md3 md4 hdf hdh
# do
#	dd bs=1k count=4k if=/dev/$d of=$d.vgda
# done
# tar cf Lutz_Reinegger.vgda.tar *.vgda
# rm *.vgda
# bzip2 Lutz_Reinegger.vgda.tar


Regards,
Heinz    -- The LVM Guy --



On Tue, Sep 30, 2003 at 09:59:19PM +0200, SystemError wrote:
> Hello out there,
> 
> after I migrating my precious volume group "datavg" from unmirrored
> disks to linux software raid devices I ran into serios problems.
> (Although I fear the biggest problem here was my own incompetence...)
> 
> First I moved the data from the old unmirrored disks away, using pvmove.
> No Problems so far.
> 
> At a certain point I had emptied the 2 PVs "/dev/hdh" and "/dev/hdf".
> So I did a vgreduce on them, then created a new raid1 
> "/dev/md4" (containing both "hdf" and "hdh") and added it to my 
> volume group "datavg" using pvcreate(->"/dev/md4") and vgextend.
> No Problems so far.
> 
> Everything looked soooo perfect and so I decided to reboot the system...
> 
> At this point things started to go wrong, during the boot sequence
> "/dev/md4" was not automatically activated and suddenly the PV
> "/dev/hdf" showed up in "datavg", "/dev/md4" was gone.
> 
> Unfortunately I paniced and ran a vgexport on "datavg", fixed the broken
> initialisation of "/dev/md4", and rebooted again. 
> This was a probably a baaad idea. 
> Shame upon me.
> 
> Now my pvscan looks like this:
> "
> [root@athens root]# pvscan 
> pvscan -- reading all physical volumes (this may take a while...)
> pvscan -- ACTIVE   PV "/dev/md2" of VG "sysvg" [16 GB / 10 GB free]
> pvscan -- inactive PV "/dev/md3" is in EXPORTED VG "datavg" [132.25 GB /
> 0 free]
> pvscan -- inactive PV "/dev/md4"  is associated to unknown VG "datavg"
> (run vgscan)
> pvscan -- WARNING: physical volume "/dev/hdh" belongs to a meta device
> pvscan -- inactive PV "/dev/hdf"  is in EXPORTED VG "datavg" [57.12 GB /
> 50.88 GB free]
> pvscan -- total: 5 [262.97 GB] / in use: 5 [262.97 GB] / in no VG: 0 [0]
> "
> 
> Or with the -u option:
> "
> [root@athens root]# pvscan -u
> pvscan -- reading all physical volumes (this may take a while...)
> pvscan -- ACTIVE   PV "/dev/md2" with UUID
> "g6Au3J-2C4H-Ifjo-iESu-4yp8-aRQv-ozChyW" of VG "sysvg"        [16 GB /
> 10 GB free]
> pvscan -- inactive PV "/dev/md3" with UUID
> "R15mli-TFs2-214J-YTBh-Hatl-erbL-G7WS4b"  is in EXPORTED VG "datavg"
> [132.25 GB / 0 free]
> pvscan -- inactive PV "/dev/md4" with UUID
> "szAa6A-rNM7-FmeU-6DHl-rKmZ-SePL-IURwtg"  is in EXPORTED VG "datavg"
> [57.12 GB / 50.88 GB free]
> pvscan -- WARNING: physical volume "/dev/hdh" belongs to a meta device
> pvscan -- inactive PV "/dev/hdf" with UUID
> "szAa6A-rNM7-FmeU-6DHl-rKmZ-SePL-IURwtg"  is in EXPORTED VG "datavg"
> [57.12 GB / 50.88 GB free]
> pvscan -- total: 5 [262.97 GB] / in use: 5 [262.97 GB] / in no VG: 0 [0]
> 
> "
> 
> A vgimport using "md3"(no probs with this raid1) and "md4" fails: 
> "
> [root@athens root]# vgimport datavg /dev/md3 /dev/md4
> vgimport -- ERROR "pv_read(): multiple device" reading physical volume
> "/dev/md4"
> "
> 
> Using "md3" and "hdh" also fails:
> "
> [root@athens root]# vgimport datavg /dev/md3 /dev/hdh
> vgimport -- ERROR "pv_read(): multiple device" reading physical volume
> "/dev/hdh"
> "
> 
> It also fails when I try to use "hdf", only the error message is
> different:
> "
> [root@athens root]# vgimport datavg /dev/md3 /dev/hdf
> vgimport -- ERROR: wrong number of physical volumes to import volume
> group "datavg"
> "
> 
> So here I am, with a huge VG an tons of data in it but no way to access
> the VG. Has anybody out there an idea how I can still access
> the data of datavg ?
> 
> By the way: 
> I am using RedHatLinux 9.0 with the lvm-1.0.3-12 binary rpm package
> as provided by RedHat.
> 
> Bye
> In desperation
> Lutz Reinegger
> 
> PS:
> Any comments and suggestions are highly appreciated, even if those
> suggestions include the use of hex editors or sacrificing 
> caffeine to dark and ancient deities.
> ;-)
> 
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
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> 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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