[linux-lvm] Symbol not found when pvcreating...

[linux-lvm] Symbol not found when pvcreating...

[David Vidal Rodriguez]

Hi (again)!
When running the CVS version of kernel+tools, the pvcreate utility
requests the following symbol that apparently isn't present in the
liblvm-10.so.0 library:
int pv_check_partitioned_whole(char *pv_name)

(Error loading shared libraries... blahblah)
An older version of pvcreate (I'm no sure if beta6 or less) does the job
correctly.
Do I have to change anything in the sources in order to get it working?

Another --developer-- question:
I've looked at the LVM code and a structure called partition, #include'd
from <linux/genhd.h>, which contains the relevant information of a
partition. What I don't understand is how to get this information from
the kernel/drive (syscall, ioctl???). I'd be glad if somebody explained
that to me briefly.

Thanks!
--
  ------------------------------------------------------------------------
 David Vidal R. (vidalrod <at> in DOT tum DOT de)

Re: [linux-lvm] Symbol not found when pvcreating...

[Heinz J. Mauelshagen]

David,

looks like a messy installation :-(

Did you try to remove and completely reinstall LVM based on a clean
compile/build run of the tools and library?


On Fri, May 25, 2001 at 05:38:36PM +0200, David Vidal Rodriguez wrote:
> Hi (again)!
> When running the CVS version of kernel+tools, the pvcreate utility
> requests the following symbol that apparently isn't present in the
> liblvm-10.so.0 library:
> int pv_check_partitioned_whole(char *pv_name)
> 
> (Error loading shared libraries... blahblah)
> An older version of pvcreate (I'm no sure if beta6 or less) does the job
> correctly.
> Do I have to change anything in the sources in order to get it working?

No.

> 
> Another --developer-- question:
> I've looked at the LVM code and a structure called partition, #include'd
> from <linux/genhd.h>, which contains the relevant information of a
> partition. What I don't understand is how to get this information from
> the kernel/drive (syscall, ioctl???). I'd be glad if somebody explained
> that to me briefly.

That's just needed for the generic disk interface.
It doesn't make any sense to create a partition table on a logical volume.

You could get the virtual geometry (which has nothing to do with the
underlying physical device(s)) of a logical volume though by doing
a block ioctl on its device like:


#include <stdio.h>
#include <fcntl.h>
#include <linux/hdreg.h>

int main ( int argc, char **argv) {
   int fd;
   struct hd_geometry hd;

   if ( ( fd = open ( argv[1], O_RDONLY)) == -1) return 1;

   ioctl ( fd, HDIO_GETGEO, &hd);
   close ( fd);
   printf ( "heads    : %d\n", hd.heads);
   printf ( "sectors  : %d\n", hd.sectors);
   printf ( "cylinders: %d\n", hd.cylinders);
   printf ( "start    : %d\n", hd.start);

   return 0;
}

> 
> Thanks!
> --
>   ------------------------------------------------------------------------
>  David Vidal R. (vidalrod <at> in DOT tum DOT de)
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html

-- 

Regards,
Heinz    -- The LVM Guy --

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@Sistina.com                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Re: [linux-lvm] Symbol not found when pvcreating...

[David Vidal Rodriguez]

>
> > Another --developer-- question:
> > I've looked at the LVM code and a structure called partition, #include'd
> > from <linux/genhd.h>, which contains the relevant information of a
> > partition. What I don't understand is how to get this information from
> > the kernel/drive (syscall, ioctl???). I'd be glad if somebody explained
> > that to me briefly.
>
> That's just needed for the generic disk interface.
> It doesn't make any sense to create a partition table on a logical volume.

What I meant is how to get the partition data, such as partition id, start, end,
etc.,  from a _real_ partition (you have get it in order to know if we are
initializing a PV on a partition marked as 0x8E). That sounds a bit off-topic, I
know...

Cheers,
--
  ------------------------------------------------------------------------
 David Vidal R. (vidalrod <at> in DOT tum DOT de)
 http://dvr.ismad.com
 "Ein Computer ohne Windows ist wie ein Fisch ohne Fahrrad."

Re: [linux-lvm] Symbol not found when pvcreating...

[Heinz J. Mauelshagen]

On Mon, May 28, 2001 at 01:21:48PM +0200, David Vidal Rodriguez wrote:
> >
> > > Another --developer-- question:
> > > I've looked at the LVM code and a structure called partition, #include'd
> > > from <linux/genhd.h>, which contains the relevant information of a
> > > partition. What I don't understand is how to get this information from
> > > the kernel/drive (syscall, ioctl???). I'd be glad if somebody explained
> > > that to me briefly.
> >
> > That's just needed for the generic disk interface.
> > It doesn't make any sense to create a partition table on a logical volume.
> 
> What I meant is how to get the partition data, such as partition id, start, end,
> etc.,  from a _real_ partition (you have get it in order to know if we are
> initializing a PV on a partition marked as 0x8E). That sounds a bit off-topic, I
> know...

Well, you can get it with my example; excluding the partition
type identifier :-(

TTBOMK you can use the e2fsprogs library to get that as well.


> 
> Cheers,
> --
>   ------------------------------------------------------------------------
>  David Vidal R. (vidalrod <at> in DOT tum DOT de)
>  http://dvr.ismad.com
>  "Ein Computer ohne Windows ist wie ein Fisch ohne Fahrrad."
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html

-- 

Regards,
Heinz    -- The LVM Guy --

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@Sistina.com                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-