[linux-lvm] Help! unable to mount lv's - can't see why!

Heinz J . Mauelshagen mauelshagen at sistina.com
Fri Sep 20 04:51:00 UTC 2002


On Fri, Sep 20, 2002 at 11:53:55AM +0200, Robin Edgar - Tripany wrote:
> Thanks! I got hde1 back on the vg and I can access it now - I'm surprised
> that the dd'ed hdb1 couldn't mount the lv's!
> I'm now wondering why the dd copy wouldn't work, because in principle it
> should have copied all the faulty blocks exactly (I did it @ 1k block
> size)...
> Last question (hopefully :)):
> does pvmove delete all the files after it has copyed all the files or is it
> copy a file, delete a file - I'm worried about the PC hanging during the
> operation..

It copies LV extents which are typically 4MB in size rather than files.
That happens at the block device, not at the file system level.

The worst thing which can extremely seldom happen (for eg. because your machine
has a power outage) is, that a metadata restore is needed.
Don't worry, that's *very* seldom :-)

Regards,
Heinz    -- The LVM Guy --

> 
> Robin
> 
> ----- Original Message -----
> From: "Heinz J . Mauelshagen" <mauelshagen at sistina.com>
> To: <linux-lvm at sistina.com>
> Sent: Thursday, September 19, 2002 9:07 PM
> Subject: Re: [linux-lvm] Help! unable to mount lv's - can't see why!
> 
> 
> > On Thu, Sep 19, 2002 at 05:01:46PM +0200, Robin Edgar - Tripany wrote:
> > > Due to the dd the 2 disks should be identical - how do i get the VG to
> > > activate the PV of choice? I can't figure out how to deactivate hdb1 and
> > > activate hde1 or how vgchange decides it wants to use hdb1 instead of
> hde1!
> >
> > Zero the first block of hdb1 (dd if=/dev/zero of=/dev/hdb1 bs=1k count=1)
> or
> > create a new physical volume on /dev/hdb1 (pvcreate -ff /dev/hdb1).
> >
> > Regards,
> > Heinz    -- The LVM Guy --
> >
> > >
> > > Robin
> > >
> > > > On Thu, Sep 19, 2002 at 12:45:47PM +0200, Robin Edgar - Tripany wrote:
> > > > > Fair enough, but I would very much like to access the files and
> > > determine
> > > > > later what has errors and what doesn't - at the moment, I can only
> do
> > > this
> > > > > with the docu lv and none of the others...
> > > > >
> > > > > You were right, I did manage to get a whole load of lost+found
> entries
> > > using
> > > > > fsck after the mount. The docu entry was on the physical extent
> though,
> > > and
> > > > > seems to be working fine.
> > > > > Anyway I thought I'd upgrade LVM to 1.0.5 from 1.0.1 and refit the
> disks
> > > to
> > > > > the 'old' configuration (4 disks + 1 for backup), to do a pvmove.
> > > > > Now when I do a pvscan, it finds all the disks, but also the disk I
> did
> > > the
> > > > > dd to, as part of the vg. So I de-activated the vg, and tried to
> reduce
> > > the
> > > > > vg /dev/hdb1, hoiwever this is not working:
> > > > >
> > > > > # vgreduce tripserv_vol /dev/hdb1
> > > > > vgreduce -- ERROR: can't reduce volume group "tripserv_vol" by used
> > > physical
> > > > > volume "/dev/hdb1"
> > > >
> > > > Well, LVM  still has allocated extents on that PV. You can just remove
> > > > empty PVs from a VG.
> > > >
> > > > >
> > > > > # pvscan -v
> > > > > pvscan -- reading all physical volumes (this may take a while...)
> > > > > pvscan -- walking through all physical volumes found
> > > > > pvscan -- ACTIVE   PV "/dev/hdg1" of VG "tripserv_vol" [38.16 GB /
> 7.93
> > > GB
> > > > > free]
> > > > > pvscan -- ACTIVE   PV "/dev/hdh1" of VG "tripserv_vol" [38.16 GB /
> 8.01
> > > GB
> > > > > free]
> > > > > pvscan -- inactive PV "/dev/hde1" of VG "tripserv_vol" [55.91 GB / 0
> > > free]
> > > > > pvscan -- ACTIVE   PV "/dev/hdf1" of VG "tripserv_vol" [55.91 GB /
> 3.37
> > > GB
> > > > > free]
> > > > > pvscan -- ACTIVE   PV "/dev/hdb1" of VG "tripserv_vol" [55.91 GB / 0
> > > free]
> > > > > pvscan -- total: 5 [244.08 GB] / in use: 5 [244.08 GB] / in no VG: 0
> [0]
> > > > >
> > > > > If i vgchange -a n it will deactivate them all, but then I get:
> > > > > # vgreduce tripserv_vol /dev/hdb1
> > > > > vgreduce -- ERROR: volume group "tripserv_vol" is not active
> > > >
> > > > Doesn't change the situation, because the PV still has extents
> allocated.
> > > > A PV must be empty and the VG active in order to remove it from the
> VG.
> > > >
> > > > >
> > > > > After I restore the vg to it's 'old' configuration, I want to empty
> > > > > /dev/hdb1 and add it to the volume group. Then doing a pvmove -i
> > > /dev/hde1
> > > > > should move all the data it can find there to the rest of the vg
> > > shouldn't
> > > > > it?
> > > >
> > > > Yes, presuming that you've got enought space to fit all extents
> allocated
> > > > to /dev/hde1.
> > > >
> > > > >
> > > > > Thank you for all your help so far,
> > > >
> > > > You're welcome.
> > > >
> > > > Regards,
> > > > Heinz    -- The LVM Guy --
> > > >
> > > > > Robin Edgar
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "Heinz J . Mauelshagen" <mauelshagen at sistina.com>
> > > > > To: <linux-lvm at sistina.com>
> > > > > Sent: Thursday, September 19, 2002 12:04 PM
> > > > > Subject: Re: [linux-lvm] Help! unable to mount lv's - can't see why!
> > > > >
> > > > >
> > > > > > On Wed, Sep 18, 2002 at 04:42:54PM +0200, Robin Edgar - Tripany
> wrote:
> > > > > > > Doing the lvdisplay -v shows that pv /dev/hde1 had bits of all
> of
> > > the
> > > > > lv's
> > > > > > > on it (including the docu lv, which I *can* mount).
> > > > > >
> > > > > > Then it is most likely, that all filesystems will have errors.
> > > > > >
> > > > > > Regards,
> > > > > > Heinz    -- The LVM Guy --
> > > > > >
> > > > > >
> > > > > > >
> > > > > > > ----- Original Message -----
> > > > > > > From: "Heinz J . Mauelshagen" <mauelshagen at sistina.com>
> > > > > > > To: <linux-lvm at sistina.com>
> > > > > > > Sent: Wednesday, September 18, 2002 3:59 PM
> > > > > > > Subject: Re: [linux-lvm] Help! unable to mount lv's - can't see
> why!
> > > > > > >
> > > > > > >
> > > > > > > > On Wed, Sep 18, 2002 at 03:56:36PM +0200, Robin Edgar -
> Tripany
> > > wrote:
> > > > > > > > > I've discovered that there is a problem with /all/ the
> > > superblocks
> > > > > > > except for those of the /docu lv (see below). It does lead me to
> > > another
> > > > > > > question though - only one of the HDs crashed: is it possible
> that
> > > LVM
> > > > > wrote
> > > > > > > all the superblocks on 1 HD?! If so this seems like a pretty
> serious
> > > bug
> > > > > in
> > > > > > <SNIP>
> > > > > > > > linux-lvm mailing list
> > > > > > > > linux-lvm at 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 at sistina.com
> > > > > > > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > > > > > > read the LVM HOW-TO at
> http://www.sistina.com/lvm/Pages/howto.html
> > > > > >
> > > > > > *** Software bugs are stupid.
> > > > > >     Nevertheless it needs not so stupid people to solve them ***
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > linux-lvm mailing list
> > > > > > linux-lvm at 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 at sistina.com
> > > > > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > > > > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> > > >
> > > > *** Software bugs are stupid.
> > > >     Nevertheless it needs not so stupid people to solve them ***
> > > >
> > > > _______________________________________________
> > > > linux-lvm mailing list
> > > > linux-lvm at 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 at 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 at 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 at 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 ***

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

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




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