[linux-lvm] LV recovery

[linux-lvm] LV recovery

[Lawrence Strydom]

Hi,
My company uses a SuSE email server III solution. The box has 2 IDE
drives, hda with /boot, /, and swap partintions on. The second, hdc, was
placed in a LVG with a LV for /var occupying all availlable space.
While I was away (quick absolution of self) one of the junior guys did
an online update of the software after which the system wouldn't start
again. To make a long story short, I managed to get the system going
again BUT..... /var cannot be mounted. 
/etc/fstab points to /dev/system/VAR. Upon inspection, this binary file
turns out to contain nothing but an error message about being unable to
write to /lib/modules/2.4.18-nnnnn/modules.dep. Ooops...
Now my question is this: Is it possible to recover the data from the
/var LV if the /dev/system/VAR file has gone AWOL? 
Any pointers to documentation/tools will be very much appreciated.

Thanks,
Lawrence

Re: [linux-lvm] LV recovery

[Heinz J . Mauelshagen]

Lawrence,

vgscan should recognize your VG fine if nothing overwrote the LVM metadata
on /dev/hdc.
What does vgscan dispay ?

On Mon, Dec 09, 2002 at 02:45:36PM +0200, Lawrence Strydom wrote:
> Hi,
> My company uses a SuSE email server III solution. The box has 2 IDE
> drives, hda with /boot, /, and swap partintions on. The second, hdc, was
> placed in a LVG with a LV for /var occupying all availlable space.
> While I was away (quick absolution of self) one of the junior guys did
> an online update of the software after which the system wouldn't start
> again. To make a long story short, I managed to get the system going
> again BUT..... /var cannot be mounted. 
> /etc/fstab points to /dev/system/VAR. Upon inspection, this binary file
> turns out to contain nothing but an error message about being unable to
> write to /lib/modules/2.4.18-nnnnn/modules.dep. Ooops...
> Now my question is this: Is it possible to recover the data from the
> /var LV if the /dev/system/VAR file has gone AWOL? 
> Any pointers to documentation/tools will be very much appreciated.
> 
> Thanks,
> Lawrence
> 
> 
> 
> 
> _______________________________________________
> 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
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Re: [linux-lvm] LV recovery

[Lawrence Strydom]

Hi Heinz,
I get the following output:
insmod: /lib/modules/2.4.7-4GB/kernel/drivers/md/lvm-mod.o: insmod
char-major-109 failed.

vgscan --  LVM driver module not loaded

That freaks me out a bit because the module is present. When I try to
load it manually with insmod I get the same error. Does this mean the
metadata has been overwritten?

Thanks
Lawrence

On Mon, 2002-12-09 at 15:30, Heinz J . Mauelshagen wrote:
> 
> Lawrence,
> 
> vgscan should recognize your VG fine if nothing overwrote the LVM metadata
> on /dev/hdc.
> What does vgscan dispay ?
> 
> On Mon, Dec 09, 2002 at 02:45:36PM +0200, Lawrence Strydom wrote:
> > Hi,
> > My company uses a SuSE email server III solution. The box has 2 IDE
> > drives, hda with /boot, /, and swap partintions on. The second, hdc, was
> > placed in a LVG with a LV for /var occupying all availlable space.
> > While I was away (quick absolution of self) one of the junior guys did
> > an online update of the software after which the system wouldn't start
> > again. To make a long story short, I managed to get the system going
> > again BUT..... /var cannot be mounted. 
> > /etc/fstab points to /dev/system/VAR. Upon inspection, this binary file
> > turns out to contain nothing but an error message about being unable to
> > write to /lib/modules/2.4.18-nnnnn/modules.dep. Ooops...
> > Now my question is this: Is it possible to recover the data from the
> > /var LV if the /dev/system/VAR file has gone AWOL? 
> > Any pointers to documentation/tools will be very much appreciated.
> > 
> > Thanks,
> > Lawrence
> > 
> > 
> > 
> > 
> > _______________________________________________
> > 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/

Re: [linux-lvm] LV recovery

[Heinz J . Mauelshagen]

On Mon, Dec 09, 2002 at 05:33:58PM +0200, Lawrence Strydom wrote:
> Hi Heinz,
> I get the following output:
> insmod: /lib/modules/2.4.7-4GB/kernel/drivers/md/lvm-mod.o: insmod
> char-major-109 failed.
> 
> vgscan --  LVM driver module not loaded
> 
> That freaks me out a bit because the module is present. When I try to
> load it manually with insmod I get the same error. Does this mean the
> metadata has been overwritten?

No, it does only mean that insmod fails loading the lvm modules which is
likely caused by the depmod problem not being able to write the module
dependency file. Is your root filesystem full ? In that case you need to
free some space there in order to run "depmod -a" fine.
If you didn't boot the Linux version you want to create the module dependency
file(s) for, you may need "depmod -F System.map -a Linuxversion".

If the modules can't be loaded or the LVM driver is not statically
bound into your kernel, you can't activate any volume groups and therefore
can't access any logical volumes :(

BTW: You are using a rather old version of the 2.4 kernel and likely of LVM too.
     Is there a chance that you can upgrade ?

Regards,
Heinz    -- The LVM Guy --

> 
> Thanks
> Lawrence
> 
> On Mon, 2002-12-09 at 15:30, Heinz J . Mauelshagen wrote:
> > 
> > Lawrence,
> > 
> > vgscan should recognize your VG fine if nothing overwrote the LVM metadata
> > on /dev/hdc.
> > What does vgscan dispay ?
> > 
> > On Mon, Dec 09, 2002 at 02:45:36PM +0200, Lawrence Strydom wrote:
> > > Hi,
> > > My company uses a SuSE email server III solution. The box has 2 IDE
> > > drives, hda with /boot, /, and swap partintions on. The second, hdc, was
> > > placed in a LVG with a LV for /var occupying all availlable space.
> > > While I was away (quick absolution of self) one of the junior guys did
> > > an online update of the software after which the system wouldn't start
> > > again. To make a long story short, I managed to get the system going
> > > again BUT..... /var cannot be mounted. 
> > > /etc/fstab points to /dev/system/VAR. Upon inspection, this binary file
> > > turns out to contain nothing but an error message about being unable to
> > > write to /lib/modules/2.4.18-nnnnn/modules.dep. Ooops...
> > > Now my question is this: Is it possible to recover the data from the
> > > /var LV if the /dev/system/VAR file has gone AWOL? 
> > > Any pointers to documentation/tools will be very much appreciated.
> > > 
> > > Thanks,
> > > Lawrence
> > > 
> > > 
> > > 
> > > 
> > > _______________________________________________
> > > 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 ***

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

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

Re: [linux-lvm] LV recovery

[Lawrence Strydom]

Thanks for the help Heinz. I actually managed to get it going with a bit
of a long-winded route though. I installed the SuSE email server III
software on another machine and configured it with a small VG to make
sure the modules are all there. Then I removed hdc from the broken
machine, put in the new machine and ran vgscan again. Vgscan correctly 
identified my LV and created /etc/lvmtab and /etc/lvmtab.d. After that
it was a simple matter of editting /etc/fstab to mount /var on
/dev/system/VAR. 

Once again, thanks for the effort :-)

Lawrence


On Mon, 2002-12-09 at 19:54, Heinz J . Mauelshagen wrote:
> On Mon, Dec 09, 2002 at 05:33:58PM +0200, Lawrence Strydom wrote:
> > Hi Heinz,
> > I get the following output:
> > insmod: /lib/modules/2.4.7-4GB/kernel/drivers/md/lvm-mod.o: insmod
> > char-major-109 failed.
> > 
> > vgscan --  LVM driver module not loaded
> > 
> > That freaks me out a bit because the module is present. When I try to
> > load it manually with insmod I get the same error. Does this mean the
> > metadata has been overwritten?
> 
> No, it does only mean that insmod fails loading the lvm modules which is
> likely caused by the depmod problem not being able to write the module
> dependency file. Is your root filesystem full ? In that case you need to
> free some space there in order to run "depmod -a" fine.
> If you didn't boot the Linux version you want to create the module dependency
> file(s) for, you may need "depmod -F System.map -a Linuxversion".
> 
> If the modules can't be loaded or the LVM driver is not statically
> bound into your kernel, you can't activate any volume groups and therefore
> can't access any logical volumes :(
> 
> BTW: You are using a rather old version of the 2.4 kernel and likely of LVM too.
>      Is there a chance that you can upgrade ?
> 
> Regards,
> Heinz    -- The LVM Guy --
> 
> > 
> > Thanks
> > Lawrence
> > 
> > On Mon, 2002-12-09 at 15:30, Heinz J . Mauelshagen wrote:
> > > 
> > > Lawrence,
> > > 
> > > vgscan should recognize your VG fine if nothing overwrote the LVM metadata
> > > on /dev/hdc.
> > > What does vgscan dispay ?
> > > 
> > > On Mon, Dec 09, 2002 at 02:45:36PM +0200, Lawrence Strydom wrote:
> > > > Hi,
> > > > My company uses a SuSE email server III solution. The box has 2 IDE
> > > > drives, hda with /boot, /, and swap partintions on. The second, hdc, was
> > > > placed in a LVG with a LV for /var occupying all availlable space.
> > > > While I was away (quick absolution of self) one of the junior guys did
> > > > an online update of the software after which the system wouldn't start
> > > > again. To make a long story short, I managed to get the system going
> > > > again BUT..... /var cannot be mounted. 
> > > > /etc/fstab points to /dev/system/VAR. Upon inspection, this binary file
> > > > turns out to contain nothing but an error message about being unable to
> > > > write to /lib/modules/2.4.18-nnnnn/modules.dep. Ooops...
> > > > Now my question is this: Is it possible to recover the data from the
> > > > /var LV if the /dev/system/VAR file has gone AWOL? 
> > > > Any pointers to documentation/tools will be very much appreciated.
> > > > 
> > > > Thanks,
> > > > Lawrence
> > > > 
> > > > 
> > > > 
> > > > 
> > > > _______________________________________________
> > > > 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 ***
> 
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> 
> 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/