[CentOS] Duplicate PV on HW RAID?

Mon Jul 28 19:17:16 UTC 2008
Ross S. W. Walker <RWalker at medallion.com>

Eduardo Grosclaude wrote:
> 
> Ross, Nate, Tony, thanks for your promptly response
> 
> 
> On Mon, Jul 28, 2008 at 2:51 PM, nate <centos at linuxpowered.net> wrote:
> 
> 
> 	Eduardo Grosclaude wrote:
> 	
> 	> 4) Rebooted the installed system. Now "Duplicate PV" 
> shows at boot. Honestly
> 	
> 	
> 	To me it sounds likely that the raid controller is shitty and
> 	is presenting two sets of devices to the OS, one likely being
> 	the "RAID" device and the other a more generic device(s).
> 	
> 	What does 'dmesg' say? Do you see more devices than you think
> 	you should have on the system?
> 
> dmesg says nothing about this, the message only appears at 
> console when booting or otherwise using the PVs:
> 
> [root at myserver ~]# pvs
>   Found duplicate PV 8D7K2wg15HqD0l9HxZCz7QlDfpqJOhXT: using 
> /dev/sdb2 not /dev/sda2
>   PV         VG         Fmt  Attr PSize   PFree
>   /dev/sdb2  VolGroup00 lvm2 a-   465,62G    0 
> 
> [root at myserver ~]# lvs
>   Found duplicate PV 8D7K2wg15HqD0l9HxZCz7QlDfpqJOhXT: using 
> /dev/sdb2 not /dev/sda2
>   LV       VG         Attr   LSize   Origin Snap%  Move Log Copy% 
>   LogVol00 VolGroup00 -wi-ao 150,00G                              
>   LogVol01 VolGroup00 -wi-ao   1,94G                              
>   LogVol02 VolGroup00 -wi-ao 313,69G   
> 
> 
> [root at myserver ~]# sfdisk -d
> # tabla de particiones de /dev/sda
> unit: sectors
> 
> /dev/sda1 : start=       63, size=   208782, Id=83, bootable
> /dev/sda2 : start=   208845, size=976543155, Id=8e
> /dev/sda3 : start=        0, size=        0, Id= 0
> /dev/sda4 : start=        0, size=        0, Id= 0
> # tabla de particiones de /dev/sdb
> unit: sectors
> 
> /dev/sdb1 : start=       63, size=   208782, Id=83, bootable
> /dev/sdb2 : start=   208845, size=976543155, Id=8e
> /dev/sdb3 : start=        0, size=        0, Id= 0
> /dev/sdb4 : start=        0, size=        0, Id= 0
> 
> Awful--I expected to see just one device :P 
> 
> > There might be a disk from an old RAID1 set in there.
> Don't think so, this machine was integrated here with new materials.
> 
> Oops... system-config-lvm shows under 'Uninitialized entities':
> /dev/sda
>      -> part 1
>      -> part 2
>      -> unpartitioned space
> /dev/sdb
>      -> part 1
>      -> unpartitioned space

The sfdisk output looks OK, I think it's just an issue with
system-config-lvm getting confused with the "leaky" sdb.

> These shouldn't be appearing as two discs in the first 
> place-- but anaconda said I only had one unit...
> Anyway, why the asymmetry? Did I screw the RAID volume 
> somehow? Or did I install plain on sda and this RAID never 
> worked as such? :P

I think it's the on board RAID not abstracting the disks as
it should.

> The machine BIOS correctly describes the RAID volume at 
> start. Doesn't It smell like fake RAID?
> Should I declare sdb invalid to the firmware program so as to 
> force resync?

You could re-try the installation, or, hide /dev/sdb from lvm
using filtering in lvm.conf.

You can reboot with a live cd and run a checksum comparison
on the volumes on each disk to verify if the RAID is working
correctly. Maybe there is a BIOS option to hide drive 2?

If you do a re-install and get the same result then you know
it wasn't a mistake on your part though (unless you make it
again!).

-Ross

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