[linux-lvm] problem when creating a volumegroup on an external drive

[linux-lvm] problem when creating a volumegroup on an external drive

[Joep Blom]

Hi,
I'm new to the list and new to the use of LVM. I have read the manuals 
(which mainly are for LVM1) and am using LVM2.
I have one question. I just created a new volumegroup on an USB external 
disk.
As the manual says I did : pvcreate /dev/sda but that did't work but 
pvcreate /dev/sda1 worked.
I then did a vgcreate VG01, expecting to get one volume group for the 
whole disk (250 GB). However, it created 2 volumegroups, one named 
VolGroup00  of 46.6 GB and one VG01 (as expected) of 232.8 GB. The 
problem is I have on another 2 disks already a VolGroup00 so I cannot do 
an lvcreate VolGroup00 as this will try to access the earlier created one.
Can anybody explain why an unrequested volumegroup is created and how 
can I solve this.
I cannot do a vgdelete VolGroup00 as this will destroy my current - 
working - system.
Hope somebody knows the answers.
Thanks
Joep

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Patrick Caulfield]

Joep Blom wrote:
> Hi,
> I'm new to the list and new to the use of LVM. I have read the manuals
> (which mainly are for LVM1) and am using LVM2.
> I have one question. I just created a new volumegroup on an USB external
> disk.
> As the manual says I did : pvcreate /dev/sda but that did't work but
> pvcreate /dev/sda1 worked.
> I then did a vgcreate VG01, expecting to get one volume group for the
> whole disk (250 GB). However, it created 2 volumegroups, one named
> VolGroup00  of 46.6 GB and one VG01 (as expected) of 232.8 GB. The
> problem is I have on another 2 disks already a VolGroup00 so I cannot do
> an lvcreate VolGroup00 as this will try to access the earlier created one.
> Can anybody explain why an unrequested volumegroup is created and how
> can I solve this.
> I cannot do a vgdelete VolGroup00 as this will destroy my current -
> working - system.
> Hope somebody knows the answers.


It's fantastically unlikely that a single 'vgcreate VG0' command would create
two VGs.

What is much more likely is that VolGroup00 already existed and you just
didn't notice it. That's the default name for a volume group created by a
Fedora install BTW

patrick

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Joep Blom]

Patrick Caulfield wrote:

>Joep Blom wrote:
>  
>
>>Hi,
>>I'm new to the list and new to the use of LVM. I have read the manuals
>>(which mainly are for LVM1) and am using LVM2.
>>I have one question. I just created a new volumegroup on an USB external
>>disk.
>>
>>    
>>
>
>
>It's fantastically unlikely that a single 'vgcreate VG0' command would create
>two VGs.
>
>What is much more likely is that VolGroup00 already existed and you just
>didn't notice it. That's the default name for a volume group created by a
>Fedora install BTW
>
>patrick
>
>_______________________________________________
>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/
>
>  
>
Patrick,
Thanks for the quick reply. However, this is external USB disk (250Gb 
and I just added it to the system as a backup disk. FC5 was running and 
before I did anything the disk was formatted as a FAT32 disk I then did 
a pvcreate. When I checked the disk was empty (as was expected). The 
vgcreate did the strange thing, which is a problem as I cant remove this 
VolGroup00 as there exists one on the other (2) disks and when I asses 
VolGroup00 it rightly goes to the original VolGroup00, which I cannot 
delete.
I think the only solution is fdisk and see if it will free the whole 
disk. But any other ideas?
Joep

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Klaus Strebel]

Joep Blom schrieb:
> Patrick Caulfield wrote:
> 
>> Joep Blom wrote:
>>  
>>
>>> Hi,
>>> I'm new to the list and new to the use of LVM. I have read the manuals
>>> (which mainly are for LVM1) and am using LVM2.
>>> I have one question. I just created a new volumegroup on an USB external
>>> disk.
>>>
>>>   
>>
>>
>> It's fantastically unlikely that a single 'vgcreate VG0' command would
>> create
>> two VGs.
>>
>> What is much more likely is that VolGroup00 already existed and you just
>> didn't notice it. That's the default name for a volume group created by a
>> Fedora install BTW
>>
>> patrick
>>
>> _______________________________________________
>> 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/
>>
>>  
>>
> Patrick,
> Thanks for the quick reply. However, this is external USB disk (250Gb
> and I just added it to the system as a backup disk. FC5 was running and
> before I did anything the disk was formatted as a FAT32 disk I then did
> a pvcreate. When I checked the disk was empty (as was expected). The
> vgcreate did the strange thing, which is a problem as I cant remove this
> VolGroup00 as there exists one on the other (2) disks and when I asses
> VolGroup00 it rightly goes to the original VolGroup00, which I cannot
> delete.
> I think the only solution is fdisk and see if it will free the whole
> disk. But any other ideas?
> Joep
Hi Joep,

well, what Patrick meant is, that your system (forget that USB drive in
this moment) already has a VG called VolGroup00 on your internal disk.
The modern FC distros use it as default (i think, i'm using SuSE ;-) ).
Before messing up more using fdisk, just provide us with the output of a
vgdisplay -a ;-) get an impression of the 'disaster' :-).

Btw. the volume group your wanted to create has the name VG0, not
VolGroup00 ;-) ..

Ciao
Klaus

-- 
Mit freundlichen Gr�ssen / best regards

Klaus Strebel, Dipl.-Inform. (FH), mailto:klaus.strebel@gmx.net

/"\
\ /     ASCII RIBBON CAMPAIGN
 X        AGAINST HTML MAIL
/ \

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Joep Blom]

Klaus Strebel wrote:

>Hi Joep,
>
>well, what Patrick meant is, that your system (forget that USB drive in
>this moment) already has a VG called VolGroup00 on your internal disk.
>The modern FC distros use it as default (i think, i'm using SuSE ;-) ).
>Before messing up more using fdisk, just provide us with the output of a
>vgdisplay -a ;-) get an impression of the 'disaster' :-).
>
>Btw. the volume group your wanted to create has the name VG0, not
>VolGroup00 ;-) ..
>
>Ciao
>Klaus
>
>  
>
Klaus & Pattrick,
I'm sorry I asked the wrong question (stupid me!). I interpreted the 
output of vgcreate wrongly. Yes, Klaus, the VolGroup00 was automatically 
created by FC when I did an upgrade.
The correct question is that VG01 (the name I gave it) occupies 232.88 
Gb although I had asked for 250 Gb. Where are the 17.2 GB and can I add 
them to VG01.
When I look with fdisk it says that no information is available for 
/dev/sda1 and "invalid flag 0x0000 of partition table 4 will be 
corrected by w(rite)".
I assume that all problems have arisen due to the fact that I did a 
pvcreate on a disk which has a W95 FAT32 partition ( of 250 Gb).
I assume the best way is to delete the partition completely and create a 
new partition (with parted or fdisk?) or are there better methods? Do I 
have to remove VG01 first?
Please, be lenient to me for these basic questions.
Joep

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Ming Zhang]

On Sat, 2006-05-13 at 00:25 +0200, Joep Blom wrote:
> Klaus Strebel wrote:
> 
> >Hi Joep,
> >
> >well, what Patrick meant is, that your system (forget that USB drive in
> >this moment) already has a VG called VolGroup00 on your internal disk.
> >The modern FC distros use it as default (i think, i'm using SuSE ;-) ).
> >Before messing up more using fdisk, just provide us with the output of a
> >vgdisplay -a ;-) get an impression of the 'disaster' :-).
> >
> >Btw. the volume group your wanted to create has the name VG0, not
> >VolGroup00 ;-) ..
> >
> >Ciao
> >Klaus
> >
> >  
> >
> Klaus & Pattrick,
> I'm sorry I asked the wrong question (stupid me!). I interpreted the 
> output of vgcreate wrongly. Yes, Klaus, the VolGroup00 was automatically 
> created by FC when I did an upgrade.
> The correct question is that VG01 (the name I gave it) occupies 232.88 
> Gb although I had asked for 250 Gb. Where are the 17.2 GB and can I add 


when u buy the disk, vendor count it as 250GB or 250 * 1000 * 1000 *
1000 bytes.

when LVM count it, it is 250 * 1000 * 1000 * 1000 / 1024 / 1024/ 1024 =
232.83GB.

check online, many discussion about this 1024 and 1000 issue.


> them to VG01.
> When I look with fdisk it says that no information is available for 
> /dev/sda1 and "invalid flag 0x0000 of partition table 4 will be 
> corrected by w(rite)".
> I assume that all problems have arisen due to the fact that I did a 
> pvcreate on a disk which has a W95 FAT32 partition ( of 250 Gb).
> I assume the best way is to delete the partition completely and create a 
> new partition (with parted or fdisk?) or are there better methods? Do I 
> have to remove VG01 first?
> Please, be lenient to me for these basic questions.
> Joep
> 
> 
> _______________________________________________
> 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/

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Joep Blom]

Ming Zhang wrote:

>On Sat, 2006-05-13 at 00:25 +0200, Joep Blom wrote:
>  
>
>>Klaus Strebel wrote:
>>
>>    
>>
>>>Hi Joep,
>>>
>>>well, what Patrick meant is, that your system (forget that USB drive in
>>>this moment) already has a VG called VolGroup00 on your internal disk.
>>>The modern FC distros use it as default (i think, i'm using SuSE ;-) ).
>>>Before messing up more using fdisk, just provide us with the output of a
>>>vgdisplay -a ;-) get an impression of the 'disaster' :-).
>>>
>>>Btw. the volume group your wanted to create has the name VG0, not
>>>VolGroup00 ;-) ..
>>>
>>>Ciao
>>>Klaus
>>>
>>> 
>>>
>>>      
>>>
>>Klaus & Pattrick,
>>I'm sorry I asked the wrong question (stupid me!). I interpreted the 
>>output of vgcreate wrongly. Yes, Klaus, the VolGroup00 was automatically 
>>created by FC when I did an upgrade.
>>The correct question is that VG01 (the name I gave it) occupies 232.88 
>>Gb although I had asked for 250 Gb. Where are the 17.2 GB and can I add 
>>    
>>
>
>
>when u buy the disk, vendor count it as 250GB or 250 * 1000 * 1000 *
>1000 bytes.
>
>when LVM count it, it is 250 * 1000 * 1000 * 1000 / 1024 / 1024/ 1024 =
>232.83GB.
>
>check online, many discussion about this 1024 and 1000 issue.
>
>
>  
>
>>them to VG01.
>>When I look with fdisk it says that no information is available for 
>>/dev/sda1 and "invalid flag 0x0000 of partition table 4 will be 
>>corrected by w(rite)".
>>I assume that all problems have arisen due to the fact that I did a 
>>pvcreate on a disk which has a W95 FAT32 partition ( of 250 Gb).
>>I assume the best way is to delete the partition completely and create a 
>>new partition (with parted or fdisk?) or are there better methods? Do I 
>>have to remove VG01 first?
>>Please, be lenient to me for these basic questions.
>>Joep
>>
>>
>>_______________________________________________
>>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/
>>    
>>
>
>_______________________________________________
>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/
>
>  
>
Ah, Ming,
Thanks! That solves it!.
So I don't have to remove the already created pv. Only fdisk complains 
because when I do an "fdisk /dev/sda" it sees it still as a FAT32 
partition but when I do an "fdisk /dev/sda1" it correctly sees it as a 
partition which is virtually free but with the invalid flag in partition 
table 4. As I use it as a backup disk I don't have to boot from it but 
is a logical volume bootable?
One last question: Why can't  I use "pvcreate /dev/sda" but have to use 
"pvcreate /dev/sda1" (as the LV HOW-TO stated the former).
Hope you can help me out with this as well.
Joep

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Markus Laire]

On 5/13/06, Joep Blom <jlblom@neuroweave.nl> wrote:
> One last question: Why can't  I use "pvcreate /dev/sda" but have to use
> "pvcreate /dev/sda1" (as the LV HOW-TO stated the former).
> Hope you can help me out with this as well.

pvcreate man-page says that:
<quote>
For *whole disk devices only* the partition table must be erased,
which will effectively destroy all data on that disk. This can be done
by zeroing the first sector with:
  dd if=/dev/zero of=PhysicalVolume bs=512 count=1
</quote>

-- 
Markus Laire

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Ming Zhang]

i did not follow the whole thread and thus i have no idea.

if there is no important data on it and it now does not belong to any
vg. u can use dd to wipe the first 512B and then do pvcreate as u want.

ming

On Sat, 2006-05-13 at 10:19 +0200, Joep Blom wrote:
> Ming Zhang wrote:
> 
> >On Sat, 2006-05-13 at 00:25 +0200, Joep Blom wrote:
> >  
> >
> >>Klaus Strebel wrote:
> >>
> >>    
> >>
> >>>Hi Joep,
> >>>
> >>>well, what Patrick meant is, that your system (forget that USB drive in
> >>>this moment) already has a VG called VolGroup00 on your internal disk.
> >>>The modern FC distros use it as default (i think, i'm using SuSE ;-) ).
> >>>Before messing up more using fdisk, just provide us with the output of a
> >>>vgdisplay -a ;-) get an impression of the 'disaster' :-).
> >>>
> >>>Btw. the volume group your wanted to create has the name VG0, not
> >>>VolGroup00 ;-) ..
> >>>
> >>>Ciao
> >>>Klaus
> >>>
> >>> 
> >>>
> >>>      
> >>>
> >>Klaus & Pattrick,
> >>I'm sorry I asked the wrong question (stupid me!). I interpreted the 
> >>output of vgcreate wrongly. Yes, Klaus, the VolGroup00 was automatically 
> >>created by FC when I did an upgrade.
> >>The correct question is that VG01 (the name I gave it) occupies 232.88 
> >>Gb although I had asked for 250 Gb. Where are the 17.2 GB and can I add 
> >>    
> >>
> >
> >
> >when u buy the disk, vendor count it as 250GB or 250 * 1000 * 1000 *
> >1000 bytes.
> >
> >when LVM count it, it is 250 * 1000 * 1000 * 1000 / 1024 / 1024/ 1024 =
> >232.83GB.
> >
> >check online, many discussion about this 1024 and 1000 issue.
> >
> >
> >  
> >
> >>them to VG01.
> >>When I look with fdisk it says that no information is available for 
> >>/dev/sda1 and "invalid flag 0x0000 of partition table 4 will be 
> >>corrected by w(rite)".
> >>I assume that all problems have arisen due to the fact that I did a 
> >>pvcreate on a disk which has a W95 FAT32 partition ( of 250 Gb).
> >>I assume the best way is to delete the partition completely and create a 
> >>new partition (with parted or fdisk?) or are there better methods? Do I 
> >>have to remove VG01 first?
> >>Please, be lenient to me for these basic questions.
> >>Joep
> >>
> >>
> >>_______________________________________________
> >>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/
> >>    
> >>
> >
> >_______________________________________________
> >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/
> >
> >  
> >
> Ah, Ming,
> Thanks! That solves it!.
> So I don't have to remove the already created pv. Only fdisk complains 
> because when I do an "fdisk /dev/sda" it sees it still as a FAT32 
> partition but when I do an "fdisk /dev/sda1" it correctly sees it as a 
> partition which is virtually free but with the invalid flag in partition 
> table 4. As I use it as a backup disk I don't have to boot from it but 
> is a logical volume bootable?
> One last question: Why can't  I use "pvcreate /dev/sda" but have to use 
> "pvcreate /dev/sda1" (as the LV HOW-TO stated the former).
> Hope you can help me out with this as well.
> Joep
> 

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Joep Blom]

Markus Laire wrote:

> On 5/13/06, Joep Blom <jlblom@neuroweave.nl> wrote:
>
>> One last question: Why can't  I use "pvcreate /dev/sda" but have to use
>> "pvcreate /dev/sda1" (as the LV HOW-TO stated the former).
>> Hope you can help me out with this as well.
>
>
> pvcreate man-page says that:
> <quote>
> For *whole disk devices only* the partition table must be erased,
> which will effectively destroy all data on that disk. This can be done
> by zeroing the first sector with:
>  dd if=/dev/zero of=PhysicalVolume bs=512 count=1
> </quote>
>
Thanks, Marcus,
I have read that also but pvcreate (lvm2) worked nevertheless. I only 
have the warning with fdisk that it encounters an "invalid flag 0x000 in 
partition table 4 which will be corrected with write". So I simply don't 
use fdisk on that disk and I don't know if this is harmful. But thanks 
for reminding me.
Joep

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Markus Laire]

On 5/15/06, Joep Blom <jlblom@neuroweave.nl> wrote:
> Markus Laire wrote:
> > pvcreate man-page says that:
> > <quote>
> > For *whole disk devices only* the partition table must be erased,
> > which will effectively destroy all data on that disk. This can be done
> > by zeroing the first sector with:
> >  dd if=/dev/zero of=PhysicalVolume bs=512 count=1
> > </quote>
> >
> Thanks, Marcus,
> I have read that also but pvcreate (lvm2) worked nevertheless. I only
> have the warning with fdisk that it encounters an "invalid flag 0x000 in
> partition table 4 which will be corrected with write". So I simply don't
> use fdisk on that disk and I don't know if this is harmful. But thanks
> for reminding me.

Well, since fdisk is "Partition table manipulator for Linux", you
clearly shouldn't use it on disks which don't have a partition-table.
And if you use whole disk for LVM, you don't have any partitions there
(and shouldn't have partition-table either), and so fdisk is of no use
for such a disk.

-- 
Markus Laire

Re: [linux-lvm] problem when creating a volumegroup on an external drive

[Joep Blom]

Markus Laire wrote:

> On 5/15/06, Joep Blom <jlblom@neuroweave.nl> wrote:
>
>> Markus Laire wrote:
>> > pvcreate man-page says that:
>> > <quote>
>> > For *whole disk devices only* the partition table must be erased,
>> > which will effectively destroy all data on that disk. This can be done
>> > by zeroing the first sector with:
>> >  dd if=/dev/zero of=PhysicalVolume bs=512 count=1
>> > </quote>
>> >
>> Thanks, Marcus,
>> I have read that also but pvcreate (lvm2) worked nevertheless. I only
>> have the warning with fdisk that it encounters an "invalid flag 0x000 in
>> partition table 4 which will be corrected with write". So I simply don't
>> use fdisk on that disk and I don't know if this is harmful. But thanks
>> for reminding me.
>
>
> Well, since fdisk is "Partition table manipulator for Linux", you
> clearly shouldn't use it on disks which don't have a partition-table.
> And if you use whole disk for LVM, you don't have any partitions there
> (and shouldn't have partition-table either), and so fdisk is of no use
> for such a disk.
>
I agree.
Joep