LV recovery

linux-lvm Lawrence Strydom 2 participants 5 messages Dec 9, 2002

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Lawrence Strydom

author

2002-12-09 06:42 UTC #0 lore raw

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

Heinz J . Mauelshagen

2002-12-09 07:38 UTC #1 lore raw

Lawrence,

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

Quoted 26 lines · 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
_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Signature · 15 lines

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
[email protected]                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Lawrence Strydom

author

2002-12-09 09:31 UTC #2 lore raw

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

Quoted 58 lines · Heinz J . Mauelshagen

Lawrence,
vgscan should recognize your VG fine if nothing overwrote the LVM metadata on /dev/hdc.
What does vgscan dispay ?
Quoted 26 lines · 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
_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Signature · 21 lines
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
[email protected]                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Heinz J . Mauelshagen

2002-12-09 12:15 UTC #3 lore raw

Quoted 10 lines · 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?

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 --

Quoted 66 lines

Thanks
Lawrence
Quoted 29 lines · Heinz J . Mauelshagen
Lawrence,
vgscan should recognize your VG fine if nothing overwrote the LVM metadata on /dev/hdc.
What does vgscan dispay ?
Quoted 21 lines · 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
Quoted 29 lines
Quoted 5 lines
_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Signature · 21 lines
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
[email protected]                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Quoted 5 lines

_______________________________________________
linux-lvm mailing list
[email protected]
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
[email protected] +49 2626 141200

                                                       FAX 924446

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

Lawrence Strydom

author

2002-12-09 13:15 UTC #4 lore raw

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

Quoted 119 lines · Heinz J . Mauelshagen

Quoted 10 lines · 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?
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 --
Quoted 66 lines
Thanks
Lawrence
Quoted 29 lines · Heinz J . Mauelshagen
Lawrence,
vgscan should recognize your VG fine if nothing overwrote the LVM metadata on /dev/hdc.
What does vgscan dispay ?
Quoted 21 lines · 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
Quoted 29 lines
Quoted 5 lines
_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Signature · 21 lines
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
[email protected]                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Quoted 5 lines
_______________________________________________
linux-lvm mailing list
[email protected]
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
[email protected] +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
_______________________________________________
linux-lvm mailing list
[email protected]
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/