[linux-lvm] Exposing the same VG from two different disks

[liam at landv.org.uk]

Thanks to everyone who replied. The vgimportclone worked really well and I can recommend it to anyone who is in my situation. 

I have a follow up question about how the LVM filter works in the script. Should I post here or to the LVM Devel list instead?

Just in case here is the right place !!! My question is, I have multiple paths to the same disks so I have masked the individual paths (the sd devices) and just exposed the logical deives (the emcpower devices). The script loses this filter and complains about lots of duplicate PV ids as it runs through. This "problem" is purely cosmetic and doesn't seem to in anyway effect the script from working. If this is not expected behaviour and the fix is fairly straight forward I'd be more than happy to test any fix. I've had a look at trying to see where the errors are coming from but I have to admit my LVM knowledge isn't up to it.

Thanks again to everyone for their hope,
Liam



>On Fri, 2009-06-05 at 15:18 +0200, liam at landv.org.uk wrote:
>> Hi,
>> 
>> I'm not sure if what I'm trying to do is possible or not but hopefully
>>  someone out there can help!!
>> 
>> I have a volume group which consists of a LUN (/dev/emcpowerv1) in an
>>  EMC cabinet. To backup up the disk I use EMC technology to synchronise
>>  a second LUN (/dev/emcpoweraf1) with the first, when the
>>  synchronisation is complete I then break the connection. At this point
>>  I have two identical volume groups exposed to the same host. What I
>>  would like to do is rename the second volume group and mount its
>>  logical volumes. However I can't because (understandably) LVM doesn't
>>  like having two identical volume groups so when I issue pvchange -u I
>>  get...
>> 
>> 
>> # pvchange -u /dev/emcpoweraf1
>>   Found duplicate PV dXiYI6nVqu8UpXO2mlaWiKKPKSBPrRbn: using /dev/emcpowerv1 
>not /dev/emcpoweraf1
>>   get_pv_from_vg_by_id: vg_read failed to read VG !
>>   /dev/emcpowerv1: write failed after 0 of 4096 at 4096: Operation not 
>permitted
>>   pv_write with new uuid failed for /dev/emcpowerv1.
>>   0 physical volumes changed / 1 physical volume not changed
>> 
>> Notice I issue the command against /dev/emcpoweraf1 but it complains about 
>writing to /dev/emcpowerv1.
>
>Take a look at the vgimportclone script posted to the lvm-devel list
>last month:
>
>http://www.redhat.com/archives/lvm-devel/2009-May/msg00130.html
>
>Regards,
>Bryn.
>
>
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