[linux-lvm] Listing physical volumes in a volume group

[linux-lvm] Listing physical volumes in a volume group

[Steeve McCauley]

I would like to know if there is a canonical way to list the
physical volumes in a volume group, specifically to extract
the uuid for those PVs in a bash script.  I am able to do
something along the lines of,

PVS=$(vgdisplay -vv 2>&1 | grep "PV UUID" | awk '{print $3}')
PVUUID=$(pvs -o pv_uuid --noheadings /dev/sdx | awk '{print $1}')

and then look for PVUUID in the list of PVS.

for uuid in $PVS; do
   [ "$uuid" != "$PVUUID" ] && continue
   ...
done

but this relies on the output format of 'vgdisplay -vv' and
I want to be sure that I will always get the expected result.

Thanks,

steeve

-- 
Steeve McCauley
:wq

Re: [linux-lvm] Listing physical volumes in a volume group

[Milan Broz]

Hi,

this will not help for using in script ?
(comma separated list of PVS & PV UUID  in VG)

vgs --separator , --noheadings -o pv_name,pv_uuid <vgname>

Milan
--
mbroz@redhat.com

Steeve McCauley wrote:
> I would like to know if there is a canonical way to list the
> physical volumes in a volume group, specifically to extract
> the uuid for those PVs in a bash script.  I am able to do
> something along the lines of,
> 
> PVS=$(vgdisplay -vv 2>&1 | grep "PV UUID" | awk '{print $3}')
> PVUUID=$(pvs -o pv_uuid --noheadings /dev/sdx | awk '{print $1}')
> 
> and then look for PVUUID in the list of PVS.
> 
> for uuid in $PVS; do
>    [ "$uuid" != "$PVUUID" ] && continue
>    ...
> done
> 
> but this relies on the output format of 'vgdisplay -vv' and
> I want to be sure that I will always get the expected result.
> 
> Thanks,
> 
> steeve
> 

Re: [linux-lvm] Listing physical volumes in a volume group

[Steeve McCauley]

Milan,

Ah, I didn't realise one could use the pv_ column names
with the vgs utility.

That's much better.

Thanks,

steeve

Milan Broz wrote:
> Hi,
> 
> this will not help for using in script ?
> (comma separated list of PVS & PV UUID  in VG)
> 
> vgs --separator , --noheadings -o pv_name,pv_uuid <vgname>
> 
> Milan
> --
> mbroz@redhat.com
> 
> Steeve McCauley wrote:
>> I would like to know if there is a canonical way to list the
>> physical volumes in a volume group, specifically to extract
>> the uuid for those PVs in a bash script.  I am able to do
>> something along the lines of,
>>
>> PVS=$(vgdisplay -vv 2>&1 | grep "PV UUID" | awk '{print $3}')
>> PVUUID=$(pvs -o pv_uuid --noheadings /dev/sdx | awk '{print $1}')
>>
>> and then look for PVUUID in the list of PVS.
>>
>> for uuid in $PVS; do
>>    [ "$uuid" != "$PVUUID" ] && continue
>>    ...
>> done
>>
>> but this relies on the output format of 'vgdisplay -vv' and
>> I want to be sure that I will always get the expected result.
>>
>> Thanks,
>>
>> steeve
>>
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

-- 
Steeve McCauley
Director of Research and Development
Rackable Systems
407 McGill Street, Suite 1002
Montreal, Quebec, H2Y 2G3 (Canada)
Tel: 514-288-3343
http://www.rackable.com
:wq

Re: [linux-lvm] Listing physical volumes in a volume group

[Alasdair G Kergon]

On Fri, Aug 03, 2007 at 12:01:13PM -0400, Steeve McCauley wrote:
> Ah, I didn't realise one could use the pv_ column names
> with the vgs utility.
 
pvs, vgs, and lvs simply set up different defaults before entering the
same reporting engine.  One such default is what prefix to add to column
names that are supplied without any prefix.  If you request -o name,
vgs would turn that into 'vg_name' whereas pvs would turn it into
'pv_name', for example.

Use '-o help' (in sufficiently recent versions) to see the list of
fields.

Alasdair
-- 
agk@redhat.com