[linux-lvm] pvscan does not detect lvm1 exported volume group

[linux-lvm] pvscan does not detect lvm1 exported volume group

[Nico Stuurman]

While trying to upgrade from RedHat 9 (2.4 kernel) to Mandriva 2007  
(2.6 kernel) I needed to export and re-import a lvm volume group.   
The volume group is build from two RAID5 volumes on 3ware RAID  
cards.  In RedHat 9 (using lvm tools version 1.0.3) I can inactivate  
and export the volume group (using vgchange -an and vgexport).   
However, this exported volume group is not detected using the  
Mandriva 2007 system (which, I presume, uses a recent version of  
lvm2).  pvscan simply does not detect the volume group.

The relevant output of pvscan -vvvv is copied below.  The volume  
group consists of /dev/sdb1 and /dev/sdc1.  Apparently, pvscan sees  
some kind of md raid information on /dev/sdb1 and decides to skip it?

After rebooting in RedHat 9, pvscan (1.0.3) sees the volume group  
and  vgimport imports it fine.

Is there any way I can move this volume group to a kernel 2.6 system  
that uses the lvm2 tools?

Thanks!


Nico


#device/dev-io.c:437         Opened /dev/sdb RO
#device/dev-io.c:264       /dev/sdb: size is 2734359936 sectors
#device/dev-io.c:134         /dev/sdb: block size is 4096 bytes
#filters/filter.c:112         /dev/sdb: Skipping: Partition table  
signature found
#device/dev-io.c:483         Closed /dev/sdb
#device/dev-io.c:437         Opened /dev/sdb1 RO
#device/dev-io.c:264       /dev/sdb1: size is 2734359327 sectors
#device/dev-io.c:483         Closed /dev/sdb1
#device/dev-io.c:264       /dev/sdb1: size is 2734359327 sectors
#device/dev-io.c:437         Opened /dev/sdb1 RO O_DIRECT
#device/dev-io.c:134         /dev/sdb1: block size is 512 bytes
#device/dev-io.c:483         Closed /dev/sdb1
#filters/filter-md.c:39         /dev/sdb1: Skipping md component device
#filters/filter-sysfs.c:251         /dev/fd0h360: Skipping (sysfs)
#filters/filter-sysfs.c:251         /dev/fd0h720: Skipping (sysfs)
#filters/filter-sysfs.c:251         /dev/fd0u1440: Skipping (sysfs)
#filters/filter-sysfs.c:251         /dev/fd0u2880: Skipping (sysfs)
#device/dev-io.c:437         Opened /dev/sdc RO
#device/dev-io.c:264       /dev/sdc: size is 2734359936 sectors
#device/dev-io.c:134         /dev/sdc: block size is 4096 bytes
#filters/filter.c:112         /dev/sdc: Skipping: Partition table  
signature found
#device/dev-io.c:483         Closed /dev/sdc
#device/dev-io.c:437         Opened /dev/sdc1 RO
#device/dev-io.c:264       /dev/sdc1: size is 1367195697 sectors
#device/dev-io.c:483         Closed /dev/sdc1
#device/dev-io.c:264       /dev/sdc1: size is 1367195697 sectors
#device/dev-io.c:437         Opened /dev/sdc1 RO O_DIRECT
#device/dev-io.c:134         /dev/sdc1: block size is 512 bytes
#device/dev-io.c:483         Closed /dev/sdc1
#filters/filter-md.c:39         /dev/sdc1: Skipping md component device
#device/dev-io.c:437         Opened /dev/sdc2 RO
#device/dev-io.c:264       /dev/sdc2: size is 1367163630 sectors
#device/dev-io.c:483         Closed /dev/sdc2
#device/dev-io.c:264       /dev/sdc2: size is 1367163630 sectors
#device/dev-io.c:437         Opened /dev/sdc2 RO O_DIRECT
#device/dev-io.c:134         /dev/sdc2: block size is 512 bytes
#device/dev-io.c:483         Closed /dev/sdc2
#filters/filter-composite.c:31         Using /dev/sdc2
#device/dev-io.c:437         Opened /dev/sdc2 RO O_DIRECT
#device/dev-io.c:134         /dev/sdc2: block size is 512 bytes
#label/label.c:180       /dev/sdc2: No label detected
#label/label.c:278         <backtrace>
#device/dev-io.c:483         Closed /dev/sdc2

Re: [linux-lvm] pvscan does not detect lvm1 exported volume group

[Luca Berra]

On Thu, Feb 01, 2007 at 08:21:00AM -0800, Nico Stuurman wrote:
>The relevant output of pvscan -vvvv is copied below.  The volume  
>group consists of /dev/sdb1 and /dev/sdc1.  Apparently, pvscan sees  
>some kind of md raid information on /dev/sdb1 and decides to skip it?

I don't know why there is a md superblock at the end of sdb1 and sdc1,
maybe you used to mirror or stripe them before, then forgot to remove
the superblock when you quit md.
anyway you can use mdadm to examine and remove the superblock from sdb1
and sdc1.
In alternative you can disable md_component_detection in
/etc/lvm/lvm.conf (if you will never use lvm over md anymore, that is)

L.


-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] pvscan does not detect lvm1 exported volume group

[Nico Stuurman]

Thanks Luca,

I was not aware that md was ever used on the system (that is what you  
get for not configuring things yourself).  I disabled  
md_component_detection and all was fine.

Thanks!


Nico

On Feb 6, 2007, at 11:51 PM, Luca Berra wrote:

> On Thu, Feb 01, 2007 at 08:21:00AM -0800, Nico Stuurman wrote:
>> The relevant output of pvscan -vvvv is copied below.  The volume   
>> group consists of /dev/sdb1 and /dev/sdc1.  Apparently, pvscan  
>> sees  some kind of md raid information on /dev/sdb1 and decides to  
>> skip it?
>
> I don't know why there is a md superblock at the end of sdb1 and sdc1,
> maybe you used to mirror or stripe them before, then forgot to remove
> the superblock when you quit md.
> anyway you can use mdadm to examine and remove the superblock from  
> sdb1
> and sdc1.
> In alternative you can disable md_component_detection in
> /etc/lvm/lvm.conf (if you will never use lvm over md anymore, that is)
>
> L.
>
>
> -- 
> Luca Berra -- bluca@comedia.it
>        Communication Media & Services S.r.l.
> /"\
> \ /     ASCII RIBBON CAMPAIGN
>  X        AGAINST HTML MAIL
> / \
>
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