[linux-lvm] lvm/devfs bug?

[linux-lvm] lvm/devfs bug?

[Rich Turner]

i am trying to create a physical volume using the entire disk /dev/sda1
and pvcreate is complaining that there is a partition table on the disk
when in fact there isnt.

# pvcreate -ff -v /dev/sda1
pvcreate --device "/dev/sda" has a partition table

i have tried many different things:
# dd if=/dev/zero of=/dev/sda bs=1024 count=10
# blockdev --rereadpt /dev/sda

# sfdisk -R /dev/sda1

i am able to confirm that /proc/partitions does not have a partition
entry for the disk but pvcreate still fails. i am using a devfs kernel
so i thought there might be some strange behavior between lvm and devfs.
is there a fix or known issues regarding lvm and devfs?

Re: [linux-lvm] lvm/devfs bug?

[Alasdair G Kergon]

On Tue, Apr 08, 2003 at 12:21:45PM -0700, Rich Turner wrote:
> the entire disk /dev/sda1
> # pvcreate -ff -v /dev/sda1
> pvcreate --device "/dev/sda" has a partition table
> # dd if=/dev/zero of=/dev/sda bs=1024 count=10
> # blockdev --rereadpt /dev/sda
> # sfdisk -R /dev/sda1
 
Confusion between
  /dev/sda  and
  /dev/sda1 ?

Alasdair
-- 
agk@uk.sistina.com

Re: [linux-lvm] lvm/devfs bug?

[rich turner]

sorry, my mistake. i copied it from many different attempt sources. all
references should be sda not sda1 because the pv will be located on the
entire disk not a partition

On Tue, 2003-04-08 at 12:33, Alasdair G Kergon wrote:
> On Tue, Apr 08, 2003 at 12:21:45PM -0700, Rich Turner wrote:
> > the entire disk /dev/sda1
> > # pvcreate -ff -v /dev/sda1
> > pvcreate --device "/dev/sda" has a partition table
> > # dd if=/dev/zero of=/dev/sda bs=1024 count=10
> > # blockdev --rereadpt /dev/sda
> > # sfdisk -R /dev/sda1
>  
> Confusion between
>   /dev/sda  and
>   /dev/sda1 ?
> 
> Alasdair
> -- 
> agk@uk.sistina.com
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] lvm/devfs bug?

[Luca Berra]

On Tue, Apr 08, 2003 at 12:21:45PM -0700, Rich Turner wrote:
>i am able to confirm that /proc/partitions does not have a partition
>entry for the disk but pvcreate still fails. i am using a devfs kernel
>so i thought there might be some strange behavior between lvm and devfs.
>is there a fix or known issues regarding lvm and devfs?
>
if you have devfs you should use the devfs long mane to reference your pv
eg: /dev/scsi/host0/bus0/target0/lun0/disc
as to why the error message is misleading i would not say, lvm1 tools are
very buggy wrt the handling of device names.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] lvm/devfs bug?

[Rich Turner]

even though devfs is compiled in the kernel it actually is not mounted
at this time. i have tried it using devfs long names also with no
success.

On Tue, 2003-04-08 at 13:43, Luca Berra wrote:
> On Tue, Apr 08, 2003 at 12:21:45PM -0700, Rich Turner wrote:
> >i am able to confirm that /proc/partitions does not have a partition
> >entry for the disk but pvcreate still fails. i am using a devfs kernel
> >so i thought there might be some strange behavior between lvm and devfs.
> >is there a fix or known issues regarding lvm and devfs?
> >
> if you have devfs you should use the devfs long mane to reference your pv
> eg: /dev/scsi/host0/bus0/target0/lun0/disc
> as to why the error message is misleading i would not say, lvm1 tools are
> very buggy wrt the handling of device names.
> 
> L.
> 
> -- 
> Luca Berra -- bluca@comedia.it
>         Communication Media & Services S.r.l.
>  /"\
>  \ /     ASCII RIBBON CAMPAIGN
>   X        AGAINST HTML MAIL
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> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
-- 
Rich Turner
Storix Software
(619)702-6500 phone
(619)702-6501 fax
http://www.storix.com

Re: [linux-lvm] lvm/devfs bug?

[Rich Turner]

its my understanding that pvcreate investigates /proc/partitions for
disk information to create the physical volume. if there are no
partitions defined on a disk in /proc/partitions then why does pvcreate
think there is a partition? am i missing something that pvcreate is
looking at to determine disk information?

On Tue, 2003-04-08 at 14:22, Rich Turner wrote:
> even though devfs is compiled in the kernel it actually is not mounted
> at this time. i have tried it using devfs long names also with no
> success.
> 
> On Tue, 2003-04-08 at 13:43, Luca Berra wrote:
> > On Tue, Apr 08, 2003 at 12:21:45PM -0700, Rich Turner wrote:
> > >i am able to confirm that /proc/partitions does not have a partition
> > >entry for the disk but pvcreate still fails. i am using a devfs kernel
> > >so i thought there might be some strange behavior between lvm and devfs.
> > >is there a fix or known issues regarding lvm and devfs?
> > >
> > if you have devfs you should use the devfs long mane to reference your pv
> > eg: /dev/scsi/host0/bus0/target0/lun0/disc
> > as to why the error message is misleading i would not say, lvm1 tools are
> > very buggy wrt the handling of device names.
> > 
> > L.
> > 
> > -- 
> > Luca Berra -- bluca@comedia.it
> >         Communication Media & Services S.r.l.
> >  /"\
> >  \ /     ASCII RIBBON CAMPAIGN
> >   X        AGAINST HTML MAIL
> >  / \
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> -- 
> Rich Turner
> Storix Software
> (619)702-6500 phone
> (619)702-6501 fax
> http://www.storix.com
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
-- 
Rich Turner
Storix Software
(619)702-6500 phone
(619)702-6501 fax
http://www.storix.com

Re: [linux-lvm] lvm/devfs bug?

[Patrick Caulfield]

On Tue, Apr 08, 2003 at 02:22:23PM -0700, Rich Turner wrote:
> even though devfs is compiled in the kernel it actually is not mounted
> at this time. i have tried it using devfs long names also with no
> success.

If devfs is in the kernel you MUST have it mounted for LVM. It's to do with the
interaction between /proc/partitions and LVM.



patrick

Re: [linux-lvm] lvm/devfs bug?

[rich turner]

i dont completely agree with that because even when i use a kernel that
does not have devfs i still get the same symptoms. even though
/proc/partitions does not have a partition for a disk pvcreate still
complains that there is one. pvcreate must be looking someplace else or
there is a bug within lvm.

now, if i create a pv within a partition there are no complaints, lvm
will continue normally. it appears to only happen when i want to create
a pv on the entire disk.

why does pvcreate think there is a partition when there clearly isnt
one?

On Wed, 2003-04-09 at 00:21, Patrick Caulfield wrote:
> On Tue, Apr 08, 2003 at 02:22:23PM -0700, Rich Turner wrote:
> > even though devfs is compiled in the kernel it actually is not mounted
> > at this time. i have tried it using devfs long names also with no
> > success.
> 
> If devfs is in the kernel you MUST have it mounted for LVM. It's to do with the
> interaction between /proc/partitions and LVM.
> 
> 
> 
> patrick
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] lvm/devfs bug?

[rich turner]

does anyone recognize this as a bug within lvm?

there clearly is not a partition on sda (according to /proc/partitions)
but pvcreate thinks there is one. if pvcreate examines only
/proc/partitions for disk partitions and there is not a partition on a
disk then why does pvcreate fail? i may not understand all of the
underlying behavior of pvcreate but it appears to be failing when it
shouldnt. is this a bug?

On Wed, 2003-04-09 at 16:57, rich turner wrote:
> i dont completely agree with that because even when i use a kernel that
> does not have devfs i still get the same symptoms. even though
> /proc/partitions does not have a partition for a disk pvcreate still
> complains that there is one. pvcreate must be looking someplace else or
> there is a bug within lvm.
> 
> now, if i create a pv within a partition there are no complaints, lvm
> will continue normally. it appears to only happen when i want to create
> a pv on the entire disk.
> 
> why does pvcreate think there is a partition when there clearly isnt
> one?
> 
> On Wed, 2003-04-09 at 00:21, Patrick Caulfield wrote:
> > On Tue, Apr 08, 2003 at 02:22:23PM -0700, Rich Turner wrote:
> > > even though devfs is compiled in the kernel it actually is not mounted
> > > at this time. i have tried it using devfs long names also with no
> > > success.
> > 
> > If devfs is in the kernel you MUST have it mounted for LVM. It's to do with the
> > interaction between /proc/partitions and LVM.
> > 
> > 
> > 
> > patrick
> > 
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] lvm/devfs bug?

[Kevin P. Fleming]

rich turner wrote:

> does anyone recognize this as a bug within lvm?
> 
> there clearly is not a partition on sda (according to /proc/partitions)
> but pvcreate thinks there is one. if pvcreate examines only
> /proc/partitions for disk partitions and there is not a partition on a
> disk then why does pvcreate fail? i may not understand all of the
> underlying behavior of pvcreate but it appears to be failing when it
> shouldnt. is this a bug?
> 

If I remember your original message properly, the error you got from pvcreate 
was that the disk "contained a partition table". This is _not_ the same thing as 
the disk containing one or more partitions; there can very well be an empty 
partition table on the disk. This may not be the problem, but if it is, using

dd if=/dev/zero of=/dev/sda count=20

will wipe out any existing DOS-type partition table (or any other type of table 
that resides at the beginning of the disk). If you've already tried this, then 
I'd say there is definitely a bug happening.

Re: [linux-lvm] lvm/devfs bug?

[rich turner]

i have tried to clear partition table with:

i have tried many different things:
# dd if=/dev/zero of=/dev/sda bs=1024 count=10
# blockdev --rereadpt /dev/sda

# sfdisk -R /dev/sda1

following these commands /proc/partitions does not show a partition on
sda but pvcreate complains that there is.

if this is a bug then how do i submit it?

On Thu, 2003-04-10 at 12:58, Kevin P. Fleming wrote:
> rich turner wrote:
> 
> > does anyone recognize this as a bug within lvm?
> > 
> > there clearly is not a partition on sda (according to /proc/partitions)
> > but pvcreate thinks there is one. if pvcreate examines only
> > /proc/partitions for disk partitions and there is not a partition on a
> > disk then why does pvcreate fail? i may not understand all of the
> > underlying behavior of pvcreate but it appears to be failing when it
> > shouldnt. is this a bug?
> > 
> 
> If I remember your original message properly, the error you got from pvcreate 
> was that the disk "contained a partition table". This is _not_ the same thing as 
> the disk containing one or more partitions; there can very well be an empty 
> partition table on the disk. This may not be the problem, but if it is, using
> 
> dd if=/dev/zero of=/dev/sda count=20
> 
> will wipe out any existing DOS-type partition table (or any other type of table 
> that resides at the beginning of the disk). If you've already tried this, then 
> I'd say there is definitely a bug happening.
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] lvm/devfs bug?

[Luca Berra]

On Thu, Apr 10, 2003 at 11:08:14AM -0700, rich turner wrote:
>does anyone recognize this as a bug within lvm?

agreed.

there are long standing bugs in the dev scanning code of lvm1,
did you try using the devfs name (even if you don't mount devfs you can
create the device file manually)
you could also add some more info instead of requoting yourself
eg: contents of the damned /proc/partitions
which version of lvm tools are you running
output of lvmdiskscan
lvmdiskscan -d
pvcreate -d
and so on.

L.

P.S.
please don't post to the list, put it somewhere accessible.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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